US Diplomacy After Trump Returns toPower: “Unilateralism,” Isolationism, International Imbalance

In November this year, Republican Donald Trump was re-elected as President of the United States and will formally take office in January 2025. At the same time, the Republican Party won a majority in both the House and the Senate and holds a majority in the Supreme Court. This indicates that Trump and the Republicans have virtually full control over U.S. federal domestic and foreign policy.

Compared to the Biden administration and other Democratic leadership periods, Trump’s administration is expected to implement drastic changes in both domestic and foreign policies. Based on the core positions, values, and political goals of Trump and the right-wing populist-dominated Republican Party, as well as the diplomatic actions of his previous administration, this new Trump administration is almost certain to adopt an isolationist, unilateral, jungle-law approach that undermines the current international order.

The evolution of U.S. foreign policy since its founding has seen significant shifts—from the isolationism before the two world wars, to active involvement in international affairs during and after World War II, forging alliances and countering adversaries, and later, during the post-Cold War period, acting as the “world’s policeman” in a unipolar world to maintain post-Cold War international peace and order.

However, whether during the Cold War or in its aftermath, the U.S. consistently prioritized uniting its allies and maintaining relative balance among nations and regions to preserve peace and stability in international relations and the global order. Especially under Democratic administrations such as Clinton and Obama, there was greater emphasis on humanitarian and equitable elements in diplomacy, aiming to avoid overt bias in international disputes.

In contrast, Trump and the hawkish Republicans, isolationists, and “America First” advocates in his administration have abandoned these traditions. Neither during his first term nor in his upcoming presidency does Trump value alliances based on liberal democratic principles or seek to maintain regional or global balances. Instead, his administration is expected to pursue highly pragmatic, unilateral, and jungle-rule diplomacy that encourages countries to fend for themselves.

Trump and his diplomatic team’s reversal of the relatively balanced and humanitarian approach of Democratic foreign policy is most evident in the Middle East. For instance, on the Israel-Palestine issue, while Clinton, Obama, and Biden maintained strong alliances with Israel and prioritized its security, they also showed sympathy for Palestinians, striving to balance both sides in the conflict. These Democratic administrations supported Israel’s right to military self-defense while providing humanitarian aid to Palestinians and attempting to restrain Israel from excessive actions (though the constraints were often insufficient or ineffective). Over the past year, during the Israel-Gaza conflict, the Biden administration supported Israel’s counterattacks but also established humanitarian corridors for Gaza and opposed Israeli strikes on civilians. Similarly, regarding another key ally, Saudi Arabia, Obama and Hillary Clinton repeatedly urged democratic reforms, while Biden criticized Saudi attacks on Yemen’s Houthi forces, which caused significant civilian casualties, and reduced U.S. military support to Saudi Arabia. Toward adversary Iran, although relations remained adversarial with sanctions, Democratic administrations were willing to engage with Iranian moderates and sought peaceful resolutions to the nuclear issue through international mediation.

In stark contrast, Trump and his team have offered unconditional and unreserved support for Israel. For example, in 2018, the Trump administration recognized Jerusalem—a disputed city between Israelis and Palestinians—as Israel’s capital (contrary to the international consensus of Tel Aviv). It also recognized Israel’s sovereignty over the annexed Golan Heights in Syria, drastically cut humanitarian aid to Palestinians, and tolerated Israel’s violent suppression and shooting of Palestinian protesters. Similarly, Trump offered unconditional backing to Saudi Arabia, providing military assistance for its bombing campaign in Yemen and avoiding any punishment for Saudi Crown Prince Mohammed bin Salman’s role in the brutal killing of Washington Post journalist Jamal Khashoggi. Regarding Iran, Trump’s administration unilaterally withdrew from the Iran nuclear deal and intensified sanctions, even though Iran had not violated the agreement. Furthermore, Trump ordered the assassination of Qasem Soleimani, a top Iranian military leader and the country’s third-most powerful figure.

Trump’s second term is expected to continue the same Middle East policies as his first, repeating similar actions, including unconditionally supporting allies like Israel and Saudi Arabia while relentlessly suppressing adversaries like Iran, with which the U.S. has longstanding grievances. The U.S. might even launch a full-scale invasion of Iran or conduct carpet-bombing campaigns, making the Middle East even more uncontrollable. Recent escalations in the Syrian civil war, with sudden shifts in the situation and Turkish-backed opposition forces rapidly seizing territories, are partly connected to Trump’s election. His return to power and the loosening of U.S. control over global hotspots have emboldened various factions to disrupt regional balances by relying on brute force.

Trump’s “unilateral” foreign policy is not confined to the Middle East. In Latin America, he is expected to resume his strong sanctions on left-leaning Cuba and Venezuela while continuing to support right-wing populist governments across Central and South America. During his previous term, Brazil’s Jair Bolsonaro became a close ally of Trump, and in the coming four years, Argentina’s Javier Milei is likely to become a frequent guest at the White House. Hawkish diplomats like Elliott Abrams, who collaborated closely with corrupt and violent right-wing military regimes during the Cold War, will likely be reappointed by Trump to influence U.S. policy across Latin America.

In Africa, Trump will significantly reduce economic, technological, educational, and healthcare aid, particularly cutting off support for environmental protection, emissions reduction, women’s health, and abortion-related medical services—areas he already defunded during his first term when conservative policies controlled foreign aid. These cuts will worsen the already dire conditions faced by African populations, further endanger fragile ecosystems, and leave lasting, potentially irreversible damage.

While supporting allies like Israel, Saudi Arabia, and right-wing regimes in Latin America for ideological and strategic reasons, Trump is expected to alienate traditional Western allies such as the UK, France, Germany, and Canada, which are governed by centrist or left-leaning establishments and are economic competitors to the U.S. Rather than maintaining alliance frameworks like NATO and the G7, Trump is likely to distance himself from these Western nations, pursue isolationist policies, impose higher tariffs on them, and demand they shoulder more defense costs. (Recently, Trump even made territorial claims over Greenland and parts of Canada, further highlighting his hegemonic and bullying approach to diplomacy, even toward allies.)

Compared to his first term, Trump’s second term will likely see him more openly attacking establishment politicians across Western countries while aligning with and supporting far-right populist forces, such as France’s National Rally and Germany’s Alternative for Germany, helping them gain traction toward governance. This will further destabilize Europe internally, disrupting domestic order. Under Trump and a Republican Party dominated by populism, the U.S. will not offer Europe assistance or protection but will instead cause additional stress and damage.

On the Russia-Ukraine issue, Trump is expected to pressure Ukraine into concessions by reducing aid, likely pushing Kyiv to accept the loss of Crimea and parts of eastern Ukraine in exchange for peace. While this might bring reluctant acceptance if Russia halts its aggression, it could also embolden Putin to continue leveraging both coercion and military force to encroach upon Ukraine or other European nations. Such actions would pose greater threats of war and losses for Europe. Trump and the Republican Party’s indifference (or even potential “collusion” with Moscow) would only encourage Putin further.

In East Asia, Southeast Asia, and South Asia, Trump is likely to tacitly allow or even encourage nations to act independently, rather than pursuing strategies like Obama’s “Pivot to Asia” or Biden’s “Indo-Pacific Strategy,” which aimed to establish a U.S.-led framework for multilateral cooperation to maintain regional stability and counterbalance China, Russia, and North Korea. Trump and his administration are expected to significantly relax constraints on allies and reduce investments in and maintenance of alliances and the Indo-Pacific order.

Thus, countries with significant overall strength and considerable military potential—such as Japan, South Korea, Indonesia, India, and Pakistan—will have greater autonomy in deciding their foreign and military policies. This will introduce more uncertainty into regional dynamics and greater instability within these nations. Recently, South Korean President Yoon Suk-yeol’s “martial law” measures and the subsequent wave of protests, though primarily driven by domestic issues, are also linked to Trump’s election, the loosening of U.S. oversight over its allies, and the anticipated shift in U.S. relations with its allied nations. Should conflicts arise among these countries, the outcomes will increasingly depend on power and scheming rather than being resolved through reason or adherence to international norms. This trend will make inter-state relations more chaotic and lawless. Furthermore, the involvement of multiple nuclear states (and nations capable of quickly acquiring nuclear capabilities) in potential conflicts could have catastrophic consequences.

On the Taiwan issue, Trump is likely to weigh the matter purely from an economic standpoint to determine whether to defend or abandon this island that has traditionally received U.S. support. Within Trump’s administration, there will be divisions between the hawks advocating for robust support of Taiwan against China (such as Marco Rubio) and the radical isolationists (such as J.D. Vance), who, based on their ideology, might favor abandoning Taiwan. Meanwhile, Taiwan will strive to lobby for continued U.S. support, while mainland China will seek to influence Trump’s policy decisions. Taiwan’s fate will hinge on the interplay of these forces, its own efforts, and certain unpredictable factors.

In summary, Trump and his team’s second term will resemble his first, pursuing isolationist and unilateral foreign policies. However, this time, they are likely to implement these policies even more aggressively, with fewer reservations and greater “thoroughness.” Of course, the level of support for Trump’s foreign policies from the Republican establishment, as well as internal divisions among the party’s populist factions, will impact the direction, intensity, and outcomes of Trump’s diplomacy.

Overall, in the next four years (and possibly beyond), Trump and his right-wing populist team will likely accelerate the dismantling of the international system built by Democratic administrations and Republican establishment figures—a system founded on NATO and G7 alliances, guided by international law and regulations, and aimed at maintaining balance and stability. Instead, they will encourage nations to act independently, fostering a return to a more anarchic, jungle-like global order reminiscent of certain periods of imperial rivalry in world history. Such a world will inevitably see more conflict, injustice, and instability, with growing imbalances both internationally and within regions. Political and social instability within nations will also increase. This vision of the future is bleak, but it may be difficult to avoid.