Since the end of World War II, the most crucial underpinning of freedom in the world has been the vigor of the advanced liberal democracies and the alliances that bound them together. Through the Cold War, the key multilateral anchors were NATO, the expanding European Union, and the U.S.-Japan security alliance. With the end of the Cold War and the expansion of NATO and the EU to virtually all of Central and Eastern Europe, liberal democracy seemed ascendant and secure as never before in history.

Under the shrewd and relentless assault of a resurgent Russian authoritarian state, all of this has come under strain with a speed and scope that few in the West have fully comprehended, and that puts the future of liberal democracy in the world squarely where Vladimir Putin wants it: in doubt and on the defensive.

On the global chessboard, there has been no more deft and brilliant (and of late, lucky) player than Putin. From the early days of his presidency a decade and a half ago, he began to signal that he intended to make Russia great again, and that he saw this imperative as a zero-sum game: As the West gained friendships among post-communist states, Russia lost, and so everything possible had to be done to force Georgia, Ukraine, Moldova, and the Balkan states out of a Western liberal orientation and back into the greater Russian orbit.

The first dramatic salvo came in the summer of 2008, when Russia intervened militarily to back separatist forces in the enclaves of Abkhazia and South Ossetia seeking to break away from Georgia. Russia’s military assault was brief but brutal, and involved bombing civilian populations both in the disputed areas and in the rest of Georgia, as well as attacking fleeing civilians. The overconfident pro-Western president of Georgia, Mikheil Saakashvili, was dealt a painful lesson courtesy of Putin, and the two breakaway “republics” remain under Russian occupation to this day. It was the first time since the end of the Soviet Union that Russia’s military violated the sovereignty of an independent state, but it would not be the last.

Since huge swaths of society rose up in color revolutions in the former Yugoslavia in 2000, in Georgia in 2003, and in Ukraine in 2004-2005—all to protest electoral fraud and bring about a transition from authoritarianism to democracy—Putin has behaved as if obsessed with fear that the virus of mass democratic mobilization might spread to Russia itself. Neither was he prepared to condone the “loss” of key parts of the former Soviet Union, such as Georgia and Ukraine, to any potential alliance structure with the West. As the forces of Ukraine’s Orange Revolution squandered their miraculous victory in corruption and political squabbling, Putin won another victory in 2010, when the pro-Russian villain of the rigged election that prompted the 2004 uprising, Viktor Yanukovych, finally won the presidency.

But Yanukovych’s authoritarianism and pro-Russia orientation—which led him to scuttle a much hoped-for association agreement between Ukraine and the EU—increasingly outraged the Ukrainian people, who ousted him in a second people-power revolution (the Euromaidan) in February 2014. Soon thereafter, Russian troops without insignias infiltrated Crimea and, with sympathetic local actors, seized control of its infrastructure. Militarily weak and bereft of Western military support—which in any case was difficult to deliver quickly and effectively due to the distance relative to Russia’s proximity—Ukraine watched helplessly as Putin consolidated his conquest with a pseudo-referendum that endorsed Crimea’s re-absorption into Russia.

It was the first time since the Nazis marauded across Europe in World War II that the boundaries of a European country had been altered by military aggression. But Putin did not stop there. In a replay of its shadowy campaign of aggression against Georgia, Russia infiltrated its troops and equipment into the Donbas region of far eastern Ukraine, in support (and probably orchestration) of separatist forces there. It was one of those eastern Ukrainian armed groups that used a Soviet-era missile system to shoot down Malaysia Airlines Flight 17 on July 17, 2014. More blatant Russian military intervention followed, with Russia denying any involvement of its own soldiers, despite abundant evidence to the contrary. Today, Russia still occupies a portion of the Donbas region. A major swing state between West and East has been militarily violated and partially dismantled, and the story isn’t over yet.

Like President Bush with respect to the Georgia crisis in 2008, President Obama did not respond militarily to this aggression. But he was not passive. Together with the European Union, the U.S. imposed several rounds of painful economic and financial sanctions on key Russian officials, banks, and businesses. As the sanctions have broadened, they have hurt important Russian elites and seriously impaired the functioning of the Russian financial, energy, and defense sectors—not exactly a great formula for making Russia great again.

Putin has been desperate to get out from under these sanctions so that his regime can thrive domestically and internationally. His goals appear to be twofold. First, he seeks to restore some form of Russian empire—with at least informal dominion over all the territories of the former Soviet Union—while forcing the West to accept this new balance of power and treat Russia as a superpower once again. Second, he seeks to invert Woodrow Wilson’s famous call to arms and instead “make the world safe for autocracy.” Democracy is his enemy. He is smart enough to know that he cannot undermine it everywhere, but he will subvert, corrupt, and confuse it wherever he can.

And so Putin’s regime has been embarked for some years now on an opportunistic but sophisticated campaign to sabotage democracy and bend it toward his interests, not just in some marginal, fragile places but at the very core of the liberal democratic order, Europe and the United States. As The Telegraph reported in January, Western intelligence agencies have been monitoring a Russian campaign on a Cold War scale to support a wide range of European parties and actors—illiberal parties and politicians of both the far left and far right—that are sympathetic to Russia and Putin. This includes not just newer neo-fascist parties, but anti-immigrant far-right parties like the National Front of France—which obtained a 9 million euro loan from a Russian bank in 2014—and the Freedom Party of Austria, both of which have been gaining popularity for some time. While the Freedom Party lost the election for Austria’s ceremonial presidency last Sunday, its candidate, Norbert Hofer, won over 46 percent of the vote, and it remains the third-largest party in the parliament, poised to do better in the next elections.

Hofer’s defeat may temporarily slow the right-wing populist momentum across Europe, but National Front leader Marine Le Pen, who endorsed Putin’s annexation of Crimea and has called for an end to Western sanctions on Russia, could well be elected the next President of France next spring. And even if she loses, Putin is likely to be sitting pretty with the next French president. Le Pen’s principal rival, former French Prime Minister Francois Fillon, who recently won the conservative presidential primaries in France, has for years been calling for an end to sanctions on Putin and a closer relationship between France and Russia.

The romance between far-right, anti-immigrant European parties and Vladimir Putin’s Russia springs not just from practical ties of support but a shared conservative reaction against liberalism, globalization, and multiculturalism, and a celebration of Putin, in the words of the scholar Alina Polyakova, as “as a staunch defender of national sovereignty and conservative values who has challenged US influence and the idea of ‘Europe’ in a way that mirrors their own convictions.” This same spirit suffused the Brexit campaign in the U.K., whose longtime populist champion, Nigel Farage, has combined fierce demands for British independence from Europe with fawning admiration for Putin. Yet the Russian boost to Brexit did not come only from the right. Russian media lavishly praised the successful campaign for Labour Party leadership of the far-left candidate Jeremy Corbyn, a NATO and EU skeptic whose extremely tepid support for the Remain campaign contributed to the narrow victory of Brexit.

Meanwhile, the damage to liberalism in Europe was also being driven by a more brutal form of Russian intervention—in Syria. Russia’s bombing campaign there has not only tilted the war in favor of the dictator, Bashar al-Assad, who along with his allies has killed more civilians than either ISIS fighters or rebels, but it also dramatically accelerated the flow of Syrian refugees (now nearing 5 million) into other countries, including European ones. While Europe’s refugee crisis has many sources and causes, roughly 30 percent of European asylum-seekers last year were Syrian refugees, and the human exodus from that civil war has incidentally further helped to feed right-wing (pro-Putin) populist parties and movements across Europe, while undermining liberal leaders like Angela Merkel of Germany.

The destabilizing effects of the refugee crisis in Europe have been a kind of dividend of Putin’s campaign to defend his Middle East ally. But Putin has also attempted to destabilize democracies directly through methods more reminiscent of the Cold War. After Montenegro’s parliamentary elections on October 16 (which saw Putin pouring money into the pro-Russian opposition party and sympathetic media and NGOs, in an unsuccessful attempt to defeat the pro-NATO prime minister), evidence emerged of a plot involving three Russian citizens (alleged in the Montenegrin news media to be agents of the GRU, Russian military intelligence) and some 20 right-wing Serbian nationalists. Montenegrin authorities now allege they planned to stage a terrorist attack that would discredit the election outcome, assassinate the pro-Western prime minister, and topple his government.

As these political dramas and tensions have unfolded in democratic Europe, Putin’s Russia has made brilliant use of old and new forms of propaganda to exploit political divisions. The leading element of this has been RT (Russia Today) which is not only one of the most widely watched (and heavily subsidized) global sources of state television propaganda—and which claims 70 million weekly viewers and 35 million daily— but a vast social-media machinery as well. Added to this is the hidden influence of a vast network of Russian trolls—agents paid to spread disinformation and Russian propaganda points by posing as authentic and spontaneous commentators.

What began as a somewhat preposterous effusion of fake news reports spreading panic, for example, about an Ebola outbreak in the U.S., morphed into something more sinister, sophisticated, and profoundly consequential: a dedicated campaign to discredit Hillary Clinton and tilt the U.S. presidential election to Donald Trump. The army of Russian trolls started infiltrating U.S. media with conservative commentaries, playing up Clinton’s scandals and weaknesses, and widely diffusing other right-wing narratives against Clinton. The Russian government (America’s own intelligence agencies believe) hacked into the emails of the Democratic Party and of Clinton campaign chairman John Podesta and passed them on to Wikileaks to dispense in a devastating drip-drip-drip of divisive and unflattering revelations. In The Washington Post’s words, the campaign portrayed “Clinton as a criminal hiding potentially fatal health problems and preparing to hand control of the nation to a shadowy cabal of global financiers.” All of this gave Trump significantly more political traction while dispiriting and discouraging possible Clinton voters (many of whom simply stayed home in disgust). Given how close the U.S. election outcome was, it is easy to imagine that this intervention might have provided Trump with his margin of victory in the Electoral College.

We stand now at the most dangerous moment for liberal democracy since the end of World War II. There are still many more democracies worldwide today than when the Cold War ended. But outside the West, many of them are fragile or rapidly declining. Turkey is in the grip of full authoritarianism, the Philippines is sliding in that direction, and Korea and Brazil have both seen their first women presidents disgraced in eruptions of public anger over corruption and misuse of power. Some 200,000 Muslim Indonesians have flooded the streets of Jakarta demanding that the Christian governor be arrested for insulting Islam.  In much of Africa, the people still overwhelmingly want democracy, but leaders in numerous countries are dragging their systems in the opposite direction.

The greatest danger, however, is not what is happening in Asia, Africa, or Latin America. It is the alarming decay of liberal democracy in Europe and the United States, accelerated by escalating Russian efforts at subversion. Putin’s forces are on such a roll that they can no longer contain their glee. One pro-Putin Russian governor recently declared in a radio interview, “It turns out that United Russia [Putin’s political party] won the elections in America.”

Donald Trump’s election victory was an extraordinary political achievement for someone who has never held or sought political office. It drew the support of many tens of millions of voters who rallied to his themes of controlling immigration, changing the way things are done in Washington, generating economic opportunity for those left behind by globalization, or somehow just “making American great again.” But it probably would not have happened without Russia’s hacking of America’s political process—and on behalf of a candidate who had said he wanted good relations with Vladimir Putin.

Geopolitics does not have to be a zero-sum game. But great powers must recognize and defend vital interests. Having a Europe that is whole and free is a vital American interest. Enforcing the principle that established borders cannot be eviscerated by military aggression is a vital American interest—and nowhere more so than in Europe. Ensuring that an authoritarian Russian regime does not replicate its values and expand its power by subverting democracy in the heart of Europe is also a vital American interest.

The most urgent foreign-policy question now is how America will respond to the mounting threat that Putin’s Russia poses to freedom and its most important anchor, the Western alliance. Nothing will more profoundly shape the kind of world we live in than how the Trump administration responds to that challenge.