Jason Lee / Reuters

SEOUL—At a time when the struggle for supremacy between Washington and Beijing is intensifying, numerous countries—from Australia and New Zealand, to Japan and South Korea, to Thailand, the Philippines, Brazil, and Germany—are finding themselves in an awkward position: having the United States as their security ally and China as their top trading partner.

The U.S. and Chinese governments aren’t explicitly demanding that these nations go all in with one or the other. Not yet, at least. But pressure to pick a side on specific issues—and the various contortions these countries go through to avoid doing so—has now become a recurring feature of international affairs, and could be a prelude to a broader sorting.

As with the antagonists in the Cold War, the United States and China are deterred as nuclear-weapons states from going to war. But they also can’t engage in Cold War–esque proxy wars, because China doesn’t have allies like the Soviet Union did. “The only way they can fight with each other is proxy competition” short of war, Chung Jae-ho, a China scholar at Seoul National University, told me and other reporters who traveled to Seoul as part of the Atlantic Council Korea Journalist Fellowship Program. “That means the U.S. and China come to countries in East Asia and elsewhere, asking the same exclusivity question: ‘Are you with us or against us?’”

Nowhere is this dynamic more evident than in South Korea, which is acutely sensitive to the consequences of great-power contests, given that these have over the past century played a role in Japan’s occupation of Korea, the Korean War, and the division of the peninsula during the Cold War.

South Korea relies on its military alliance with the United States to counter the existential threat from North Korea, but does more trade with China than it does with the U.S. and Japan combined. Moon Hee-sang, the speaker of South Korea’s legislature, put it starkly when we met in Seoul in April: Asking whether South Korea will “choose either China or the United States” is like “asking a child whether you like your dad or your mom,” he noted. “We cannot abandon economy for the sake of security, and we cannot abandon security for the sake of economy.”



This strategy has underwritten unprecedented prosperity in the country, leading to reluctance among South Koreans across the political spectrum “to get involved in any big fights among big boys on the block … unless our survival is at stake,” Chun Yung-woo, a former national-security adviser to the conservative South Korean President Lee Myung-bak, explained to me. “We are split between our loyalty to the alliance and our chances to sustain the lifestyle we have been enjoying.”

What happens, though, when Mom and Dad can’t stop feuding, decide to spend some time apart, and start contemplating divorce? The South Korean government has in recent years repeatedly had to grapple with the very trade-off Speaker Moon dismissed as inconceivable.

Chung, the China expert, has identified at least seven instances in which Beijing and Washington have sought to coerce Seoul into their corner—matters such as South Korea’s involvement in dueling China- and U.S.-led multinational free-trade agreements, China’s new development bank, and American freedom-of-navigation operations in the South China Sea.

The real wake-up call came in 2017, when the Trump administration pressed current South Korean President Moon Jae-in to permit the deployment of a U.S. missile-defense system known as THAAD, which China considers a threat and Moon himself had criticized during his election campaign. Beijing retaliated by punishing South Korean businesses operating in China and halting Chinese tourism to South Korea. South Koreans became aware of “how harsh [the Chinese] can be in dealing with their small neighbors and how hollow their commitment to a peaceful rise actually turned out to be,” said Chun, the former official. “The romantic view of China is gone now.”

Forced to weigh the economy against security, Moon effectively selected all of the above, ordering a (still ongoing) assessment of THAAD’s environmental impact that has left the deployment in limbo and its attendant geopolitical questions unresolved. The South Korean government partially patched things up with China by promising to not carry out additional THAAD deployments or enter into a military alliance with Japan and the United States.

In the case of the brawl over THAAD, the Trump administration exposed an ally doing the U.S. a favor to Beijing’s wrath and then left it to fend for itself. It did the same when China detained Canadians and blocked imports of Canadian canola oil as revenge for Canada arresting a Chinese technology executive at America’s request. The pattern is unlikely to inspire other countries wrestling with the “Mom-Dad” dilemma to go out on a limb for the United States.

Nevertheless, Moon made a significant announcement in June that got overshadowed, because it came right before Donald Trump met the North Korean leader Kim Jong Un in the demilitarized zone. Standing beside the U.S. president, he vowed to “find common ground” between the Trump administration’s Indo-Pacific Strategy for counteracting China and his own New Southern Policy, an effort to reduce South Korea’s dependence on China by building up economic relations with India and Southeast Asian nations. Prior to this, the South Korean president had resisted enlisting in (or, for that matter, rejecting membership in) either the Indo-Pacific Strategy or China’s rival Belt and Road infrastructure initiative.

As Park Jae-kyung, the coordinator for the Presidential Committee on New Southern Policy, told me this spring, that initiative and the New Northern Policy regarding Russia and northeastern Asian countries have been geared toward South Korea “rebalancing” and “diversify[ing] our foreign diplomacy and our external trade partners.” The competition between the United States and China, which account for almost 40 percent of South Korea’s exports and more than 30 percent of its imports, is only “one aspect” of the New Southern Policy, he explained, but the expectation is that these tensions will “escalate to other fields like cyberspace or even outer space … Since we are heavily dependent on these two countries, we are now trying to strengthen our new partners.”

Still, it’s unclear whether Moon has really committed to anything new that would alienate China, such as participating in U.S.-led multinational military exercises in the South China Sea. Since making the pledge, Moon’s government has threatened to scrap a military-intelligence-sharing agreement with Japan over a trade spat, which doesn’t exactly bode well for the “trilateral security cooperation” that the United States, South Korea, and Japan say they’re pursuing.

Underscoring all the tumult in the region, Russia and China conducted their first joint air patrol near disputed islands in the Sea of Japan earlier this week, prompting the South Korean military to fire warning shots at a Russian plane and the Japanese government to lash out at both Moscow and Seoul for their actions.

Japan stands out among countries caught between the superpowers in that it has largely sided with the United States amid territorial and historical conflicts with China. But even the Japanese have been quietly increasing cooperation with China on finance and infrastructure projects as a hedge against Trump’s shaky commitment to their alliance. Prime Minister Shinzo Abe has bought “insurance [from the Chinese] for when things go wrong,” Park Cheol-hee, an East Asia scholar at Seoul National University, told me and other journalists. “We have to open our eyes to the possibility that Japan and China are developing a new corporate partnership even though they hate each other.”

South Korea’s ambivalent stance extends to the debate over the Chinese telecommunications company Huawei, which takes in about a sixth of South Korea’s electronics-parts exports to China. The Trump administration has banned sales of American technology to Huawei and urged U.S. allies such as South Korea to not do business with the firm, because of alleged national-security risks associated with its connections to the Chinese government.

But when I met this spring with Peter Ha, an executive with SK Telecom, South Korea’s leading wireless provider, just as the country became the first in the world to launch 5G mobile networks nationwide, he didn’t rule out a future partnership with Huawei. “Business will be business,” he said to me and other reporters. (SK Telecom and another operator, KT, currently use equipment from the South Korean company Samsung, a Huawei competitor. But the third player in the market, LG Uplus, employs Huawei technology.)

Kim Joon-hyung, a former foreign-policy adviser to Moon’s presidential campaign, told me that the South Korean president also believes that his effort to reconcile with North Korea will help prevent Seoul from being squeezed between the United States and China. For example, he explained, “if we have a good relationship with the North, then we can say that we don’t need THAAD.”

The U.S. and South Korean push for a comprehensive peace and denuclearization deal with North Korea, which so far has made little progress, could paradoxically also inflame great-power strife in Asia if the diplomatic campaign actually succeeds. Some experts have gone so far as to suggest that North Korea may be interested in entering into a security alliance with the United States against China, which the Kim regime has long distrusted and resented its dependence on, even though they appear to have close relations.

If North Korea gives up its nuclear weapons and ends hostilities with the United States, China will argue that there’s no longer a rationale for the U.S. troop presence in South Korea and possibly Japan as well, and demand the withdrawal of American forces, Lee Seong-hyon, a China expert at the Sejong Institute, outside of Seoul, told me. Washington might in turn encourage “North Korea to defect from the Chinese camp,” which would conjure the long-standing Chinese fear of a U.S. ally materializing “right across the Yalu River.” China doesn’t want North Korea to have nuclear weapons, Lee said, but it prefers the “status quo” with North Korea over a negotiated resolution of the North Korean nuclear issue, because the latter would raise the question of “What’s next?” North Korea, of course, could also side with none of the major powers surrounding it and instead play them off one another.

When I mentioned the prospect of a future alliance between the United States and the two Koreas to a senior South Korean official, speaking on condition of anonymity to me and other journalists in April to discuss the sensitive talks with North Korea, the official said it was “difficult to imagine,” but added that the U.S.–South Korea alliance could persevere even after peace and denuclearization to address “a more comprehensive security threat as well as contingencies near the Korean peninsula.” Asked whether that was an oblique reference to China, the official smiled and said, “There are a lot of countries near the Korean peninsula.”

This is the world we now live in. The United States, alarmed about its decline, is pulling every string imaginable to reshape the world in a manner more favorable to its interests—even strings no one knew existed. (Designating Canada a national-security threat?) Meanwhile, China’s flashes of fury, from sanctioning South Korea over the deployment of THAAD to banning imports of bananas from the Philippines over territorial disputes, have offered a different lesson: An ascendant China has a whole bunch of strings it hasn’t pulled yet.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.