Amid all the talk about the Democratic Party’s move to the left, a contrary phenomenon has gone comparatively unnoticed: On foreign policy, Washington Democrats keep attacking Donald Trump from the right. They’re not criticizing him merely for his lackluster response to Russia’s interference in the 2016 elections. They’re criticizing him for seeking a rapprochement with key American adversaries and for potentially reducing America’s military footprint overseas.

In June, Senate Minority Leader Chuck Schumer reprimanded Trump for meeting with Kim Jong Un and warned him not to weaken sanctions absent the complete “dismantlement and removal of North Korea’s nuclear weapons and ballistic missile programs.” That same month, Democratic senators criticized the president for agreeing to suspend military exercises with South Korea and introduced legislation to block him from withdrawing troops from the Korean peninsula. Before Trump’s July trip to Europe, 44 Democrats on the House Armed Services and Foreign Affairs Committees urged him to maintain sanctions against Russia until it returns Crimea to Ukraine, to shun any cooperation between the American and Russian militaries, and to remain open to admitting new members to NATO.

There are other issues—notably Iran—on which Trump remains the more bellicose party. But overall, the partisan contours of the Washington foreign-policy debate have shifted markedly since the Obama years. On North Korea, Russia, and NATO, Democrats in Congress sound a lot like the Never Trump hawks who once called them appeasers.

But the more Washington Democrats echo GOP or ex-GOP hawks, the more they distance themselves from their party’s own base. Polls suggest that rank-and-file Democrats are more supportive than rank-and-file Republicans of decreasing America’s military presence overseas and more skeptical of higher defense spending and of relying on military force to combat terrorism. On her website, Alexandria Ocasio-Cortez blasts “corporate Democrats [who] seem to find the cash to fund a $1.1 trillion fighter jet program” and are “re-fighting the Cold War with a new arms race that nobody can win.”

Beneath this intra-Democratic rift lies an argument about the past quarter century of American foreign policy. Since the end of the Cold War, the United States has sought a unipolar world in which no country enjoys a sphere of influence except for the United States. As part of that strategy, America has expanded its commitments overseas on the implicit assumption that ordinary Americans benefit as America’s global footprint grows. But many ordinary Americans disagree. In 1943, the columnist Walter Lippmann said the goal of American foreign policy was to serve as the “shield of the republic”: to shape an external environment that protects freedom and prosperity at home. And for many Americans, by many measures—including growing federal debt, stagnant income growth, and degrading infrastructure—the republic during this period of overseas expansion has not fared well.

The result has been a crisis of foreign-policy “solvency.” The term is Lippmann’s. A government’s international commitments, he argued, resemble its financial commitments. Just as it cannot indefinitely incur debts that exceed its ability to pay, it cannot indefinitely incur overseas obligations that exceed its power. A nation’s power consists not merely of money and guns. In a democracy, it also consists of the public’s willingness to deploy them. And when a nation’s obligations exceed that power, the scales must eventually—often painfully—be brought back into balance.

Donald Trump rode this solvency crisis into the White House. In his incoherent and immoral way, he has challenged the assumption that the pursuit of unipolarity serves average Americans. His presidency presents Democrats with a choice. They can defend unipolarity, and join the Never Trumpers in defining a foreign-policy agenda that blends Hillary Clinton’s worldview and Marco Rubio’s. Or they can listen to their base, which has its own qualms about the expansive, interventionist foreign-policy course America has taken over the past quarter century. They can try to fortify a post–Cold War intellectual edifice that is crumbling, or they can recover an older, wiser tradition of American foreign policy better suited to the realities of this new age.

In 1992, a year after the Soviet Union fell, George H. W. Bush’s Pentagon issued a draft paper aimed at defining America’s role in the world. It declared that the United States would pursue a strategy of “deterring potential competitors from even aspiring to a larger regional or global role.” When leaked to The New York Times, the draft sparked controversy, and the Bush administration softened its language. But until Trump, every subsequent president effectively followed its path. Each tried to turn what Charles Krauthammer in 1990 termed “the Unipolar Moment” into the permanent condition of world affairs.

In different ways, and to different degrees, each sought to use the Soviet Union’s collapse to extend the scope of American military power. Bush ushered a unified Germany into NATO and, through the Gulf War, dramatically enlarged America’s military footprint in the Persian Gulf. Bill Clinton expanded NATO into Poland, Hungary, and the Czech Republic. George W. Bush ensconced NATO in the former Soviet Union itself while invading and occupying Iraq and Afghanistan, two ex-Soviet allies. Even Barack Obama, although accused of retrenchment, added two more Eastern European countries to NATO, helped install a pro-Western government in Ukraine, waged a war that led to the overthrow of Libya’s Muammar Qaddafi, deployed American troops to Australia and the Philippines in a bid to reassert America’s presence in Asia, increased American drone strikes by a factor of 10, and dramatically expanded America’s military operations in Africa.

Trump’s critics rightly accuse him of threatening the international order that America built after World War II. But it’s important to distinguish that order—built upon the United Nations, the World Bank and International Monetary Fund, the General Agreement on Tariffs and Trade (which later became the World Trade Organization), the American alliance with Japan, and a NATO that ended in Berlin—from the quest for unipolarity that America has pursued for the past quarter century. Franklin D. Roosevelt did not imagine a postwar world in which America dominated every region of the globe. To the contrary, he envisioned “four policemen”—the U.S., the Soviet Union, Britain, and China (with France added to the UN Security Council at Winston Churchill’s request)—each walking the beat in its area and cooperating to ensure that Germany and Japan never again troubled the peace.

Even after FDR’s effort to preserve the wartime alliance failed, and Washington and Moscow slid into Cold War, American policy makers never seriously challenged the Soviet Union’s sphere of influence in Eastern Europe. Dwight Eisenhower watched as the Soviets crushed uprisings in East Germany in 1953 and Hungary in 1956. Lyndon B. Johnson did the same when Russian tanks rolled into Czechoslovakia in 1968. In 1981, when Poland’s Soviet-backed government imposed martial law in an attempt to crush the independent Solidarity labor movement, Ronald Reagan—despite his thunderous anti-communist rhetoric—imposed only mild sanctions and never contemplated military action.

The brutal way Moscow dominated its neighborhood appalled American leaders. But they did not risk war to prevent it because they did not believe American freedom and American prosperity were at stake. The rationale for American intervention in World War II that FDR began articulating after Germany conquered France in 1940, and around which George Kennan built his arguments for containing the U.S.S.R. later that decade, was that America must prevent an adversary, or collection of adversaries, from dominating the industrial centers of Europe and Asia and the oil fields of the Persian Gulf. If an enemy consolidated control over these power centers, it might stop the United States from trading across the Atlantic and Pacific or deny it access to oil, either of which would wreck America’s economy. A hostile hegemon might also encroach into the Western Hemisphere, which would so menace American security that, even if the United States forestalled foreign invasion, it would become an illiberal, garrison state.

Keeping America safe, therefore, did not require denying the Soviets a sphere of influence in Eastern Europe. It merely required preventing them from extending that sphere across Western Europe or the Middle East and thus threatening the Americas. Obviously, Cold War presidents sometimes acted in reckless and immoral ways. They overthrew democratic governments in Iran and Guatemala, supported apartheid South Africa, and laid waste to Vietnam. But, particularly in Europe, the existence of a rival superpower imposed limits on America’s foreign policy. The United States fought the Nazis, contained the Soviets, and helped build the postwar order that Trump’s critics celebrate today less to establish a unipolar world than to prevent one.

In the decades since the Cold War ended, this once-familiar logic has been largely forgotten. When the Soviet Union fell, the specter that haunted Roosevelt and his successors—a hostile power or powers dominating Europe and Asia and setting their sights on the Western Hemisphere—became so remote that it could no longer guide foreign-policy debate. What filled the gap was a bipartisan ethic of “more.” If the Soviet empire had demarcated the limits of American power, then a world without those limits—in which America and Americanism dominated ever larger swaths of the globe—constituted progress. If some American hegemony was good, more American hegemony was better. In the 1940s, foreign-policy elites generally asked: What must America do overseas to ensure its freedom and prosperity at home? Since the 1990s, they have more often asked: What must America do at home to ensure its preeminence overseas?

Over the past quarter century, this ethic of “more” has contributed to a vast expansion of America’s international commitments—commitments the American people have repeatedly proved unwilling to bear. The Bush administration greased public support for invading Iraq by insisting that within months the U.S. would withdraw most of its troops. But as those predictions proved untrue—and the war grew ever costlier and bloodier—public opinion soured. George W. Bush held out against the demand to withdraw troops for a few years, even sending reinforcements in the 2007 “surge.” By 2008, however, with violence down but Iraq still extremely fragile, he caved to popular opinion and agreed to withdraw all U.S. troops by the end of 2011. Obama carried out that agreement and Iraq plunged back into civil war.

Because Afghanistan was al-Qaeda’s base on 9/11, and because the U.S. has kept its troop levels there comparatively low, popular support for that war has proved easier to sustain. But the Afghan War also underscores America’s solvency problem. It is politically sustainable because the United States currently deploys only 15,000 troops there. However, few military experts believe that is enough to defeat the Taliban or even force them into a political settlement. So the United States can continue fighting in Afghanistan only because America’s leaders do not ask Americans to expend the blood and treasure there necessary to achieve Trump’s stated goal of “creat[ing] the conditions for a political process to achieve a lasting peace.”

Still, foreign-policy elites keep proposing interventions that enjoy too little public support to succeed. In 2011, despite polling suggesting public wariness, Obama helped NATO facilitate the overthrow of Muammar Qaddafi. Libya soon dissolved into chaos. It’s questionable whether any amount of nation building could have stabilized the country after Qaddafi’s fall. But either way, Americans lacked the appetite for it, and so the United States failed to secure Libya, too.

The exception to this pattern has been the military campaign America launched in 2014 against ISIS, which, like the Afghan War, enjoyed public support because Americans viewed it as a response to direct attacks on them. Now that that war is largely over, Trump advisers have proposed keeping U.S. troops in Syria to counter Iran. Trump himself seems skeptical, likely because he grasps what polls show: that absent a direct threat, Americans remain opposed to expanding America’s military footprint in the Middle East.

With the war against ISIS dying down, Defense Secretary James Mattis declared in January that “great-power competition—not terrorism—is now the primary focus of U.S. national security.” But in its relationships with great powers, America’s solvency problems are, if anything, worse. That’s because the United States—in keeping with its general post–Cold War reluctance to grant competitors a sphere of influence—has tried to extend its power right up to the borders of Russia and China. That risks sparking conflict in places that the Russian and Chinese governments consider crucial to their security but the American people do not consider crucial to theirs. Which means yet more promises the American government cannot keep.

Consider American policy toward Russia. During the Cold War, no American president considered Eastern Europe important enough to American security to risk war over. But in the 1990s, with Russia enfeebled, many policy makers assumed that risk had disappeared. So the Clinton administration moved to admit the former Warsaw Pact countries of Poland, Hungary, and the Czech Republic into NATO, thus making their defense an American obligation.

When Trump recently questioned America’s obligation to NATO’s newest member, Montenegro, he provoked outrage. But it’s worth remembering that in the 1990s, Americans far wiser than Trump considered even Clinton’s NATO expansion a dangerous extension of America’s commitments. George Kennan, America’s most famous Cold War strategist, warned that the move would “inflame the nationalistic, anti-Western and militaristic tendencies in Russian opinion.” John Lewis Gaddis, America’s most famous Cold War historian, insisted it was “short-sighted” for Americans to believe that “the Russians have no choice but to accept what NATO has decided to do” because Russia “retains a considerable capacity to do harm.”

More than 20 years later, NATO’s expansion to include Montenegro and the former Soviet Republics of Estonia, Latvia, and Lithuania makes Kennan’s and Gaddis’s concerns all the more relevant. Could an American president rally the American people to defend a country near Russia’s border that some of them may never have heard of? Is that commitment solvent? We simply don’t know.

This doesn’t mean Democrats should abrogate America’s NATO commitments—or even publicly question them, as Trump has. NATO has helped undergird an unprecedented era of European freedom, prosperity, and peace. Reneging on America’s commitment to any member could destroy the alliance as a whole, with consequences no one can foresee. So honoring America’s commitment to its newest members is a risk Democrats must take.

But since it is a risk, the post–Cold War pattern of expanding NATO with little public discussion—since 1996, the subject has rarely come up in presidential debates—should end. The lesson of the past decade is that pushing NATO ever closer to Russia’s borders dangerously exacerbates America’s solvency gap.

Consider what has happened in Georgia and Ukraine. In 2008, the Bush administration convinced its European allies to pledge that both countries would eventually enter NATO. Enraged, Russian officials threatened to help Georgia’s two autonomous and largely pro-Russian regions, Abkhazia and South Ossetia, secede. And when Georgia’s pro-American president sent troops into South Ossetia that August, Russia did just that—it recognized Abkhazian and South Ossetian independence, blockaded Georgia’s coast, and bombed its capital. Moscow made the same point, even more harshly, a half-decade later in Ukraine, when protesters helped replace a pro-Russian government with a pro-Western one. The United States celebrated the shift of power. But Vladimir Putin responded by seizing the Crimean peninsula and fomenting an armed secessionist movement in Ukraine’s heavily Russian-speaking east, thus plunging the country into civil war.

In 2015, Joe Biden told the Ukrainian Parliament, “We will not recognize any nation having a sphere of influence. Sovereign states have the right to make their own decisions and choose their own alliances.” That sentiment still governs the attitude of many congressional Democrats today. It’s why they demand that Trump maintain American sanctions until Russia relinquishes Crimea—even though barely anyone believes American sanctions can bring that about. It’s why they support arming Ukraine with lethal weapons. And it’s why they insist on keeping open the possibility of NATO expansion into Ukraine even as Russia stations troops on Ukrainian soil.

But Biden’s words, while stirring, were delusional. The United States does not oppose spheres of influence. It has had its own in the Western Hemisphere since 1823. It’s called the Monroe Doctrine, which declares that the U.S. will not tolerate military alliances between foreign powers and the countries to America’s south. It’s the reason Mexico cannot enter into a military alliance with Russia.

Until today’s Democrats recognize—as Cold War presidents did—that the United States cannot prevent a Russian sphere of influence in those territories in which the Russian government is willing to lose lives but the American people are not, Democratic foreign policy will produce more insolvency, more promises America can’t keep.

Paul Spella

But the pursuit of unipolarity poses its greatest danger in America’s relations with China. U.S.-Chinese relations are U.S.-Russian relations in reverse. Although geopolitically aggressive, Russia is economically and demographically a declining power. It lost a large sphere of influence, and America is now seeking to deny it a smaller one. China is a rising power. It is trying to establish a sphere of influence, which America opposes. The key difference is that in the case of Russia, America’s solvency problem is static: Because Russia is not gaining economic and military strength relative to the United States and its European allies, America’s solvency problem will not grow unless it incurs new obligations. In East Asia, by contrast, China’s relative power is growing. That means America’s solvency problem—the gap between its commitment to deny China a sphere of influence and its power to do so—is growing, too.

The balance of economic power is shifting decisively in China’s favor. When the Soviet Union collapsed, America’s share of the global economy was 15 times as large as China’s. Today, it’s roughly 1.5 times as large. Experts predict that by 2040, China’s economy will be 1.5 times as large as America’s.

This economic shift is producing a military shift. Washington still spends far more than Beijing on defense, but over the past two decades the Chinese military has dramatically improved. And while the American military is spread across the world, China focuses on its own neighborhood. Thus, a 2017 Rand Corporation study concluded that “while the United States maintains unparalleled military forces overall, it faces a progressively receding frontier of military dominance in Asia. Chinese military modernization, combined with the advantages conferred by geography, have endowed China with a strong military position vis-à-vis the United States in areas close to its own territory. As a result, the balance of power between the United States and China may be approaching a series of tipping points.” The first tipping point, Rand suggests, will be Taiwan.

Taiwan is the most dangerous example of American foreign-policy insolvency in the world. The 1979 Taiwan Relations Act, signed when China’s economy was smaller than Spain’s, commits the U.S. “to maintain the capacity of the United States to resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people on Taiwan.” As Hofstra University’s Julian Ku has observed, the language is almost as strong as the language in America’s treaties with Japan, South Korea, and Australia.

This quasi-obligation is insolvent for two reasons. First, the people of mainland China care far more about Taiwan than Americans do. China’s government doesn’t merely consider Taiwan part of its sphere of influence. It considers it part of China, and has since the 17th century. In the centuries that followed, the Western powers and Japan repeatedly invaded and divided China, and many Chinese see the reunification of Taiwan as crucial to overcoming that humiliating history. This creates a vast asymmetry of public will. In 2017, the Committee of 100, a Chinese American group, asked people in both countries to name their “two greatest concerns about the U.S.-China relationship.” Among mainland Chinese, Taiwan came in first. Among Americans, it didn’t make the top seven. In fact, when asked whether the United States should defend Taiwan if it declares independence, Americans consistently, by substantial margins, say no.

Alongside this asymmetry of public will is a growing asymmetry of military power. Lyle Goldstein, a China expert at the Naval War College, notes that “China’s military modernization has steadily outstripped Taiwan’s armed forces.” And it’s not just Taiwan that’s increasingly outclassed. The United States is, too. Within 500 miles of Taiwan’s capital, notes the Rand study, China maintains 39 air-force bases. The United States maintains one, which, according to Rand, “even a relatively small number of accurate [Chinese] missiles could shut … at the outset of hostilities.” In the words of the Australian military strategist Hugh White, “America can no longer defend Taiwan from China and a policy towards Taiwan that presumes that it can is unsustainable.” In the years to come, America must either take steps to alter this unsustainable commitment or risk the possibility that China will do so itself.

So what might a Democratic alternative to both Trump and his hawkish critics—an alternative built upon the sacrifices Americans are actually willing to make rather than the obligations that unipolarity requires—look like?

It would start with the question inherent in Walter Lippmann’s phrase: What kind of shield does the American republic require in order to thrive? When Roosevelt and Kennan pondered this question in the 1940s, even America’s most powerful adversaries had trouble reaching the United States directly. The Atlantic and Pacific were formidable moats. That’s why both men worried primarily about a two-step process in which Nazi Germany or the Soviet Union first consolidated power over Eurasia and then crossed the oceans.

But since World War II, two technologies have made it easier for adversaries to bypass step one and threaten the United States without first dominating other continents. The first is nuclear weapons. Luckily, since the mid-20th century, America has pursued a strategy that has protected it against nuclear strikes by even its most fearsome foes. That strategy is nuclear deterrence, and it merely requires the United States to possess enough nuclear weapons, and sufficient means to deliver them, to credibly declare that America will destroy any regime that uses nuclear weapons against the United States. The strategy does not require foreign leaders to care about their people’s lives, only their own. Which helps explain why it worked against Joseph Stalin and Mao Zedong. And why there is every reason to believe it will work—indeed, has been working in the 12 years since North Korea’s first nuclear test—against Kim Jong Un.

Nuclear deterrence is less effective against a terrorist group with no regime or territory to protect, led by people who welcome death. But almost 17 years after September 11, the United States and its allies have proved capable of keeping nuclear weapons out of the hands of terrorists. In fact, the United States has prevented any 9/11-scale terrorist attack on American soil: Since 2001, foreign-born terrorists have killed on average one American a year inside the U.S.  

Unfortunately, the United States is less shielded from a second, more recent technology that enables direct attack: cyberwarfare. If the 2017 Intelligence Community Assessment that “Russian President Vladimir Putin ordered an influence campaign in 2016 … to undermine public faith in the US democratic process” is correct, then preventing another such attack—either on America’s elections or America’s critical infrastructure—should be among America’s highest foreign-policy priorities. Roosevelt and Kennan worried that if a hostile power dominated Europe or Asia, it could dominate the great oceans, thus leaving America so insecure that its democracy crumbled or so isolated that its economy did. Now Russia—or another adversary—can threaten American freedom and prosperity by attacking the machinery that undergirds America’s elections, banking system, or electricity grid. Few other threats put the republic itself at such risk.

So Democrats are right to blast Trump for not making cyberdefense a priority. They’re right to demand reprisals against Russia in hopes of deterring its government from repeating in 2018 and 2020 what it did in 2016. And they are right to work with America’s allies to try to deter Russia from undermining their democratic systems, too.

But in their desire to be tough on Putin, congressional Democrats are conditioning sanctions relief not only on Russia stopping its interference in American elections, but on Russia stopping its interference in Ukraine and even Syria. This combines a subject that is crucial to America’s security with subjects that are not, and defines America’s goals so expansively that they exceed America’s means. Truly guarding against Russia’s threat to the American homeland requires prioritizing it.

To protect what matters most—the integrity of its elections and those of its allies—America should compromise where it matters less: in Russia’s backyard. If Russia stops sabotaging elections in NATO countries, NATO should pledge to push no closer to Russia’s borders. Instead, the United States and its allies should pursue a status for Ukraine and Georgia similar to the status that Austria and Finland enjoyed during the Cold War. Because Soviet troops entered both countries during World War II, the United States could not deny Moscow some influence over them after the war. So each country struck a deal that granted it control over its domestic affairs (both became democracies) in return for not pursuing an anti-Soviet foreign policy. That should be America’s goal for Ukraine and Georgia today. Recognizing that U.S. sanctions almost certainly won’t reverse Russia’s annexation of Crimea, the United States might ultimately accept it as part of a deal that removed Russian troops and weaponry from Ukrainian soil.

This would not be another Warsaw Pact. It would be more like the Monroe Doctrine, as America’s leaders interpret it today. Few Americans now claim the Monroe Doctrine gives the United States the right to dictate the internal affairs of America’s neighbors to the south. If the Dominican Republic nationalizes its banks, the U.S. will not send in the Marines. But America will not permit the Dominican Republic to join a military alliance with Moscow or Beijing. America’s goal should be for Russia to follow that same principle when it comes to Georgia and Ukraine.

A similar approach should guide America’s relations with China. The U.S. must try to deter China from threatening the American homeland militarily and politically, through cyberattacks or other forms of interference. But it must also prevent China from threatening the homeland through an economic relationship that benefits American elites while weakening the American middle class.

In his book The American Way of Strategy, Michael Lind quotes Franklin D. Roosevelt as declaring in 1936 that “the very nature of free government demands that there must be a line of defense held by the yeomanry,” what we would today call the middle class. “Any elemental policy, economic or political, which tends to eliminate these dependable defenders of democratic institutions, and to concentrate control in the hands of a few small, powerful groups is directly opposed … to democratic government itself.” This concentration certainly threatens democratic government today. And preventing it should thus be central not only to American domestic policy, but to American foreign policy as well.

Trump won the presidency in part by arguing that American foreign policy focused too much on extending America’s global footprint and not enough on safeguarding America’s middle class. And he was partially right. A “shield of the republic” foreign policy would use America’s limited influence over China to protect, to whatever degree possible, American workers from competing with workers who lack even minimal labor protections. One way to do that would be to adopt a suggestion made by the Harvard economist Dani Rodrik. Rodrik notes that the United States has laws against “dumping”: It imposes tariffs on foreign goods sold in the United States for less than they cost to produce. He suggests extending such tariffs to “social dumping”: goods exported to the United States by workers without basic labor rights.

Any tariffs would have to be wielded carefully—not in the rash, jumbled way Trump has deployed them. (And certainly not against democracies whose labor protections are often better than America’s). But, as with Russia, jettisoning the assumption that America must deny China a sphere of influence might help policy makers husband American leverage for the things that matter most.

A 1949 State Department planning paper declared that the U.S. should seek to prevent the “domination of Asia by a nation or coalition of nations.” Since such domination could threaten American trade across the Pacific, and even the safety of the Western Hemisphere, precluding it should remain America’s goal. The United States can achieve that goal by maintaining its alliances with Australia, South Korea, the Philippines, and Japan and deepening its relationship with India, whose population will soon surpass China’s.

America’s commitments to these countries will only grow insolvent if the U.S. defines them as requiring it to defend disputed islands like Scarborough Shoal in the South China Sea (claimed by both China and the Philippines) or the Senkaku/Diaoyu Islands in the East China Sea (claimed by both China and Japan)—islands far from the heartlands of both U.S. allies. And that insolvency will grow worse if the United States, in its zeal to deny China a sphere of influence, takes on a new obligation—the East Asian equivalent of Ukraine and Georgia—by agreeing to defend Vietnam. Vietnam has a roughly 800-mile-long land border with China, a bevy of maritime disputes with Beijing, and a tradition of fierce anti-Chinese nationalism. The U.S. is better off helping Hanoi—in the tradition of Austria and Finland vis-à-vis the Soviet Union or, for that matter, Mexico vis-à-vis the United States—accommodate its foreign policy to the giant next door while preserving its right to manage its domestic affairs.

The most wrenching element of this strategy involves Taiwan. The island is an extraordinary success story, a powerful testament to the compatibility of democracy and Chinese culture. But the United States probably cannot defend Taiwan today. It almost certainly won’t be able to in a decade or two. If America does not face the insolvency of its current commitment to Taiwan now, it may eventually be made to face it, perhaps through war.

If China renounces the use of force, the United States should support its reunification with Taiwan along the principle of “one country, two systems.” The U.S. should ask China to commit publicly not to station troops or Communist Party officials in Taiwan, and to let Taiwan manage its domestic political affairs. Would Beijing adhere to such an agreement once unification occurred? The best precedent is Hong Kong. Two decades after reunification, it remains substantially freer than the rest of China. (Freedom House rates countries on a scale of one to seven, with one being freest and seven being least free. In 2018, Hong Kong received a 3.5 and China got a 6.5.) But Hong Kong would almost certainly be freer were it not under Beijing’s control.

It’s likely that under reunification people in Taiwan would lose some of their freedom as well. But, even if Taiwan sunk to Hong Kong’s level, it would remain far freer than Vietnam, a country some Washington hawks are clamoring to ally with in order to contain China.

There are two primary arguments against the Democratic foreign policy outlined above. The first involves credibility. If the United States abandons Taiwan, the argument goes, it will undermine the credibility of its commitment to South Korea, the Philippines, and Japan. Similarly, if America won’t fight Russia in Ukraine, neither Moscow nor Riga will believe America’s promises to fight Russia in Latvia. During the Vietnam War, this logic was dubbed the “domino theory”: If the United States didn’t defend Vietnam, its credibility would collapse and other anti-communist “dominoes” would soon fall.

But the theory is wrong. Decades of academic research show that, in the words of the Dartmouth College political scientists Daryl Press and Jennifer Lind, “there’s little evidence that supports the view that countries’ record for keeping commitments determines their credibility.” The Soviets and West Germans did not conclude that because America would not defend South Vietnam it would not defend West Berlin, because they understood that America cared more about West Berlin than it cared about South Vietnam, and had a greater capacity to defend it. Similarly, when predicting whether the United States will defend Japan, neither Beijing nor Tokyo will look at whether America defends Taiwan. They will look at whether it is in America’s interests, and within America’s power, to defend Japan.

Far from bolstering a country’s credibility, insolvent commitments drain its finances, overstretch its military, and undermine its reputation for sound judgment. As Kennan put it, “There is more respect to be won in the opinion of this world by a resolute and courageous liquidation of unsound positions than by the most stubborn pursuit of extravagant or unpromising objectives.”

The other major critique is moral: How can America let authoritarian powers bully their neighbors, especially when those neighbors only want the same freedoms that we prize in the United States? The answer begins with John F. Kennedy’s reminder that peace, too, is “a matter of human rights.” People’s lives don’t generally improve when their country becomes a battlefield. If the United States could actually defend Ukraine, Georgia, or Taiwan, then perhaps the horror of war might be worth it. But America cannot, at least not at a cost the American people would be willing to pay. Morally, therefore, America better serves these countries by helping them reach the best possible accommodation with their great-power neighbors than by encouraging their defiance with promises America can’t keep. Prudence, argued Edmund Burke, is “not only the first in rank of the virtues political and moral but … is the director, the regulator, the standard of them all.” In other words, what truly matters morally is not the purity of America’s rhetoric but the consequences of America’s policies for the people they affect most.

Morally, Americans must also consider something else: Risking conflict to deny great powers a sphere of influence in their own neighborhoods undermines the chances of cooperating with them everywhere else.

Over the past decade, American cooperation with China and Russia has proved crucial to mitigating some of the world’s greatest threats. In 2010, China, along with Russia, backed the United Nations sanctions that helped pave the way for the Iran nuclear deal. In 2014, Beijing and Washington cooperated to quell the Ebola crisis, which experts warned might infect 1.4 million West Africans. In 2016, U.S.-Chinese cooperation proved crucial to the ratification of the Paris climate-change agreement (from which Trump has subsequently withdrawn).

The more America challenges Beijing and Moscow on their borders, the harder it will be to sustain, let alone deepen, this cooperation. Only U.S.-Russian diplomacy can extend the Strategic Arms Reduction Treaty, which expires in 2021, and thus avert a costly and dangerous nuclear-arms race. Only great-power cooperation can end Syria’s monstrous civil war. The United States has some influence over the Kurds and Gulf-backed Sunni Arab rebel groups. But only Moscow, along with Iran, can deliver concessions from Bashar al-Assad’s regime. It’s the same in Afghanistan. The United States enjoys more leverage over the government in Kabul, but Russia enjoys more influence over the Taliban and China wields more influence over Pakistan.

Great-power cooperation is also crucial to easing the crisis on the Korean peninsula. No matter what he tells Trump, Kim Jong Un is unlikely to give up his nuclear weapons. But preventing further nuclear and missile tests would reduce the chances of war and facilitate the reconciliation with South Korea that could improve North Korean lives. The U.S. can’t do that alone. It can tempt Kim by promising an end to North Korea’s diplomatic and economic isolation. But it can’t fully reassure him that the United States—which turned on Qaddafi after he abandoned his own nuclear program—won’t do the same to him. Only Beijing—North Korea’s longtime ally—can do that. The more protected North Korea feels by China, the less it may feel the need to advance its nuclear program. The Naval War College’s Lyle Goldstein has suggested that Pyongyang might be more likely to permit inspection of its nuclear program if China takes part. This defies the logic of unipolarity, which mandates that the U.S. try to reduce China’s influence on the Korean peninsula. But here, too, America can better serve the cause of peace and human dignity by cooperating with great powers than seeking to supplant them.

What America needs from its foreign policy has not changed since the nation’s founding: to promote the external conditions that give Americans the best chance to become prosperous and free. What has changed, at key moments, is the strategy the United States pursues to realize those goals. In the early-19th century, via the Monroe Doctrine, the United States entered a de facto alliance with Britain—the world’s greatest naval power—to prevent Europe’s land powers from establishing beachheads in the Americas. Beginning in the early-20th century, as Britain’s ability to enforce the Monroe Doctrine waned, the United States entered two European wars, and then fought the Cold War, to prevent adversaries from dominating Europe and Asia.

Now, to achieve its enduring goals, America needs to change strategy once again. The unipolar strategy that America has pursued since the Soviet Union’s demise—of preserving if not extending American dominance in every region of the world—is increasingly insolvent. It is insolvent because America lacks the power to quell uprisings in the countries it has invaded. It is insolvent because America lacks the power to deny Russian influence over the countries on its border. It is insolvent because America lacks the power to enforce a status quo in East Asia established when China’s economy was slightly larger than Holland’s. And, above all, it is insolvent because it lacks support from the American people, who for good reason largely do not believe it has served their needs.

In this regard, Trump’s election—which followed anti-interventionist rebellions by Ross Perot, Jerry Brown, Pat Buchanan, Ralph Nader, Ron Paul, and Bernie Sanders—was a disastrous response to a legitimate and enduring discontent. The choice facing Democrats in the Trump era is whether to join a hawkish alliance that aims to suppress that discontent or whether to channel it in a progressive direction.

Hawks will denounce any foreign policy that abandons unipolarity as defeatist, a harbinger of national decline. But the progressive activists remaking the Democratic Party suspect, with good reason, that the pursuit of global dominance has been not an alternative to national decline but one of its causes. If in the coming years those activists articulate an agenda for shielding the republic—in which the U.S. protects the dignity and freedoms of its people, grants other powerful nations deference near their borders, and works with them to the solve the common problems that plague humanity—they will not be retreating from America’s best foreign-policy traditions. They will be ushering in their long overdue return.