Alliances: Resilient if shaken

The headlines

The general trend over the past two decades — including during the first Trump administration — has been one of increasing integration between the United States and its major allies; to include defence exercises, technology cooperation, forward military posture and intelligence sharing. This integration with the United States has been matched by growing minilateral security cooperation among US allies and partners, to include the US-Australia-Japan-India Quad, the addition of Australia, Japan, Korea and New Zealand (the Indo-Pacific Four) in NATO summits, and the new ‘Squad’ (US, Philippines, Japan and Australia). Though still far short of an ‘Asian NATO’, this emerging collective security architecture has moved far beyond the traditional ‘hub and spokes’ established during the Cold War to what the Biden administration officials began calling a 'latticework’ of regional security arrangements. Donald Trump’s norm-breaking second term has now cast doubt over US alliances, with some predicting allies will pursue greater autonomy or even bandwagon with China. Yet a closer examination of alliance dynamics since Trump’s second inauguration also reveals just how enduring the US alliance system is in terms of both geopolitics and US domestic factors.

President Trump’s ambivalence about alliances has been on display throughout the early days of his second term, though with a sharper focus on Europe than the Indo-Pacific. In March 2025, Trump told reporters in the Oval Office that his administration might not defend NATO allies who were unwilling to pay more for their own defence, and he excluded European partners from his peace-making efforts in the Ukraine war. In unsecured communications over Signal that same month, key members of his national security team decried European free-riding. The administration’s initial defence plans reportedly featured major cuts to US forces in Europe in favour of upgrading capabilities in the Indo-Pacific.

This intensified pressure on NATO stems from three factors: Trumps’s own personal history with President Zelenskyy of Ukraine; a long-standing disdain of Europe on the right wing of Republican politics (where there has been an historic overlap between ‘America First’ isolationism and the hardline ‘Asia First’ movement against communist China); and finally the strategic logic of pivoting US military power from Europe to the Pacific to deal with the pacing threat of China.

What Trump has not done is move to withdraw from NATO or force President Zelenskyy to accept Vladmir Putin’s terms. Nor has Trump threatened to pull troops out of Asia as he did in his 2016 campaign and then again in front of TV cameras during his 2018 summit with North Korean leader Kim Jong Un. Nevertheless, the treatment of NATO allies coupled with the Trump administration’s massive tariffs have shaken US allies everywhere.

Trump’s summit with Japanese Prime Minister Ishiba Shigeru on 7 February featured no fireworks and the two leaders’ joint statement underscored the United States’ “unwavering commitment to the defence of Japan, using its full range of capabilities, including nuclear.” Source: Getty

What is happening behind the headlines?

Despite Trump’s own mercurial approach to world affairs, the administration’s early moves with allies in the Indo-Pacific have suggested far more continuity than change. In confirmation hearings, Secretary of State Marco Rubio and Secretary of Defence Pete Hegseth emphasised their commitments to US allies. Rubio’s first major diplomatic move was a Quad foreign ministerial on 25 January that reaffirmed the partners' shared commitments to a free and open Indo-Pacific and put greater emphasis on maritime security. Trump’s summit with Japanese Prime Minister Ishiba Shigeru on 7 February featured no fireworks and the two leaders’ joint statement underscored the United States’ “unwavering commitment to the defence of Japan, using its full range of capabilities, including nuclear.” The summit statement also broke new ground in highlighting the US-Japan alliance’s readiness to respond to threats against Taiwan. On his first visit to Asia in March, Secretary Hegseth stressed that the administration would “truly prioritize and shift to this region of the world in a way that is unprecedented. Today, it’s the Philippines. Tomorrow, it’s Japan. It will be Australia and South Korea and other nations in this part of the world.” The Secretary of Defense’s visit highlighted upgrades to the US command structure in Japan, expanded defence deployments and capability-building for the Philippines, and a US$2 billion fund for security engagement in the Pacific.

More broadly, the administration’s 2026 budget proposal would increase defence spending by 13% for the next fiscal year, with a significant shift of resources towards the Indo-Pacific — an increase that enjoys support from the Republican-led Congress. The actual numbers are still unclear, however, and some senior Republicans including Senate Armed Services Committee Chair Roger Wicker, have voiced concern that the administration's actual proposal falls short of the promised $1 trillion defence budget. Whatever the overall increase, Pentagon watchers expect a significant shift of resources to the Indo Pacific from other regional commands.

However, as the proposal awaits Congressional adjudication, several senior Republicans, including Senate Armed Services Committee Chair Roger Wicker, have voiced disdain.Source: Getty

This continuity on alliances in Asia enjoys US public and Congressional support. In multiple public opinion polls, Americans have expressed strong support for US alliances, and major legislation aimed at strengthening alliances has usually passed in Congress, including the sweeping reforms of export control rules required to implement the AUKUS agreement. The architects of US security policy, including in the new Trump administration, generally recognise that the United States needs allies more rather than less in the face of China’s growing capabilities and ambitions. US forces cannot execute war plans without more distributed access, basing and overflight arrangements given the People’s Liberation Army’s numerical advantage in the Indo-Pacific. Allies like Japan and South Korea are indispensable, not only for geography but also shipbuilding and semiconductor technology needed in the competition for dominance in AI. Australia’s geography is critical as it was in the Second World War. Australia also brings other irreplaceable capabilities in areas such as critical minerals, space and intelligence. No official in the Trump administration has argued that the United States can go it alone against China in the Indo-Pacific, a point even tariff hawks like Robert Lighthizer emphasise.

At the same time, polls show that large majorities of Americans want US allies to pay more for their own defence. The administration is signalling not only in Europe but quietly to Asian allies as well that more defence spending is expected. The difference is that President Trump has thus far not publicly threatened not to defend Asian allies if they do not pay more as he did in his first presidential campaign. The United States spends 3.4% of GDP on defence (and that ratio will likely go up) compared with about 2.8% for South Korea, 1.9% for Australia and a target of 2% for Japan. NATO allies lag further behind with numbers like 1.3% for Canada (the United Kingdom will increase from its current 2.3% of GDP spending rate to 2.5% by 2027).

Even with NATO, the patterns of actual alliance cooperation continue despite the disruptive politics of the transatlantic relationship. As NATO Secretary General Mark Rutte noted after his 14 March Oval Office meeting with Trump, the US President gave a total commitment on Article V of the alliance with the exchange primarily focused on the need for European allies to do more.

Yet, despite the evidence of continuity and even strengthening of alliance relations thus far on the ground, the Trump administration’s internal turmoil and damaging tariff policy will likely continue fuelling debates about US reliability.

Key debates around the issue

Every US administration comes to power with rival factions advancing different interpretations of the President’s vision for national security, but the second Trump administration is particularly riven with competing views about how to maximise US power, primarily because the president himself views these decisions through the lens of his own personal power. The severity of China’s military growth also forces hard choices that exacerbate these debates despite broad consensus about prioritising the China challenge. Debates to watch include:

The future of the National Security Council

The NSC is generally seen as the control tower for a president’s national security strategy and implementation. The purge of Trump’s NSC leadership — reportedly at the instigation of ultranationalist social media figure Laura Loomer — came as a shock to Washington. Was the purge aimed at eliminating national security hawks? Or just those hawkish towards Iran and Russia but not China? Or has President Trump included among the institutions he wants to dismantle his own national security staff? Or was this a repeat of the chaos seen in the first Trump administration rather than a change in strategic direction? These are open questions that will have to be watched since the NSC staff play a key role in managing summits and major strategic initiatives with allies.

Allies’ own assessments of Trump

Polls among allied publics show the lowest level of trust in the United States in decades but still high support for alliance with the United States. The April Lowy Institute poll indicated that only 36% of Australians trusted the United States. Polls in Japan showed similar numbers. Yet, 80% of Australians wanted to keep the alliance with the United States and in Japan and Korea that number is close to 90%. Even in Europe there is no real appetite for abandoning NATO. Debates will continue to be bound by four considerations: (1) adversaries are increasing their threat and aligning more with each other (through the ‘CRINK’ cooperation of China, Russia, Iran and North Korea); (2) US allies’ own defence posture has been built for seven decades around US capabilities ranging from nuclear deterrence to space as well as key US defence technologies — unbundling that dependence would be incredibly costly, risky and take far longer than Trump will be in office; and (3) the sinews of alliance solidarity remain strong in the United States despite the disruption and unpredictability of Donald Trump. There are no indications of dealignment by any major US ally thus far. Instead, the doubt caused by the second Trump administration combined with growing anxiety about the CRINKs is pushing more of a focus on sustainment, designing indispensability to US forces and establishing greater sovereign defence capabilities — all of which serve US alliance objectives over the longer term. However, the element of hedging involved in these decisions is not healthy for alliances that are preparing for contingencies where trust cannot be legislated or recreated from scratch in a crisis. The debate in NATO capitals is also highly relevant for US allies in Asia given that Euro-Atlantic solidarity on China could be critical to dissuading Beijing from coercive moves in the Indo-Pacific.

US-South Korea alliance

The US ally that many in Washington think may be most at risk in Asia is South Korea. In the first Trump administration, the president himself said he would like to withdraw US troops from the Korean peninsula. While declaratory policy from the second Trump administration has thus far reiterated the US security commitment to Seoul, key officials entering the administration have long believed that the ground heavy US force posture on the Korean peninsula is of no use in Taiwan or other maritime contingencies. There is a scenario where a well-coordinated strategy between Seoul and Washington could usher in a new era of broad regional security cooperation and a South Korean lead on defence on the peninsula, but there is also a scenario, given recent volatility in both Seoul and Washington, in which a precipitous US drawdown undermines deterrence and US credibility across the region.

The structure of US and world politics would suggest more continuity than change in the US alliance system in Asia, but the volatility of President Trump’s leadership style opens other scenarios. Republicans in Congress have been most willing to defy the White House on defence policy, and Democratic control of the Congress in the 2026 mid-terms would further constrain any change in course on defence or alliance policy in the region. However, sudden announcements along the lines of Trump’s 2018 summit on North Korea would unsettle allies, and the wrong decisions in a crisis — a concern given the turmoil within the national security leadership and Trump’s own decision-making style — could have far deeper and lasting impact. Nevertheless, it is noteworthy how consistently the administration has emphasised defence commitments and security cooperation with allies in the Indo-Pacific, up to and including the president himself. The bottom line is that US alliances are resilient.

What to watch ahead

Key milestones that will test the administration’s adherence to alliances include:

• The US-Australia ‘AUSMIN’ meeting of foreign and defence ministers expected some time in the second half of the year, and a potential visit by President Trump to Australia following Australian Prime Minister Anthony Albanese’s invitation;
• The US-Japan Security Consultative Committee (‘2+2’) of defence and foreign ministers which last met in July 2024 and January 2023 and is on the table for 2025;
• The late June 2025 NATO Summit in the Netherlands;
• President Trump’s Asia travel for 2025, which he committed to Japanese Prime Minister Ishiba though the White House has not clarified whether the travel would be related to the East Asia Summit and APEC meetings later in the year or separate from those multilateral summits;
• The Quad Summit in India promised for 2025;
• Reconciliation of the House and Senate budgets and details on the Pentagon's priorities expected by July 2025.

What should allies like Australia do about it?

US allies in the Indo-Pacific like Australia are well positioned to shape the administration’s strategic posture towards the region if they step up themselves. That will require:

1. Providing greater public clarity about the nature of the security threats to Australia. There was a marked difference between Washington’s and Canberra’s public definition of the threat from China even during the Biden administration. That was before the PLA’s increased operational tempo around Australia and the incoming Trump administration’s expectations of greater efforts by allies. The 2022 Defence Strategic Review provided a framework for understanding the challenge — one that will resonate with Washington. Credibility on the China challenge will be critical to building momentum on issues important to Australia and the same is true for other US allies.

The 2022 Defence Strategic Review provided a framework for understanding the challenge — one that will resonate with Washington. Credibility on the China challenge will be critical to building momentum on issues important to Australia and the same is true for other US allies.Source: Getty

1. Examining assumptions about defence spending. The Trump administration will expect greater defence spending by all allies, including Australia. That in itself is not a reason for Australia to increase spending. However, the government would do well to re-examine its own assumptions about whether current budget plans can resource sovereign national security requirements and strategies.
2. Focusing Washington on the resilience of the Pacific and Southeast Asia. The Trump administration has employed experienced Asia Hands across the administration but in the larger struggle for influence over policy, the Pacific and Southeast Asia might fall out of focus in Washington. The US preoccupation with deterrence in North Asia, though an important priority, risks crowding out strategies for dissuasion and resilience in the Pacific and Southeast Asia. The elimination of USAID programs and attacks on the National Endowment for Democracy and other NGOs have weakened US diplomatic and soft-power in that part of the Indo-Pacific. Australia can both plug gaps and use its preferred position in Washington to keep the administration focused on parts of the Indo-Pacific that are targets for Beijing’s own strategy to undermine US alliances.
3. Work with Congress. Support for active engagement with the Indo-Pacific and solidarity with allies remains strong in Congress. Key decisions impacting US allies in the Indo-Pacific will quietly work their way through the National Defence Authorisation Act (NDAA) and other budget legislation where Republicans have proven themselves more willing to hold firm against the President’s excesses.
4. Work with Japan. Tokyo has its own headaches with respect to US tariffs, but on security policy Japan has truly established itself as the unsinkable aircraft carrier at the core of American strategy in the Indo-Pacific. Calibrating approaches with Japan will enhance Australia’s own agency in Washington and strengthen important areas of continuity in US policy.