Has Trump’s Asia tour reassured the US’s Asian allies?

Despite the president’s trip, confidence in American security guarantees is fraying. This inadvertently boosts defence spending by its key Asian allies, but risks ceding further ground to China. 

Expert comment

Published 4 November 2025 — 4 minute READ

Image — President Donald Trump and Japanese Prime Minister Sanae Takaichi hold signed documents during a meeting at Akasaka Palace on 28 October 2025 in Tokyo, Japan. (Photo by Andrew Harnik/Getty Images)

Dr Samir Puri

Former Director, Global Governance and Security Centre

President Donald Trump’s keenness for bilateral diplomacy was on full display during his tour of East and Southeast Asia last week – and so was his disdain for the patient diplomacy of multilateral forums. The Asian leaders he met were ready for this, successfully using the opportunity to curry the president’s favour. 

However, deep uncertainty remains over the reliability of the US security posture in Asia. Uncertainty is stoked by Trump’s highly personalized style of ‘America First’ diplomacy. Moreover, while US–China relations have stabilized after Trump met Chinese leader Xi Jinping in South Korea, the two superpowers remain on a collision course in Asia. 

When it comes to US regional defence aims, however, not all this uncertainty is bad. Its key strategic aim in Asia is to encourage its key regional allies to spend more on their defence – and they are obliging. South Korea’s President Lee Jay Myung has pledged to increase his defence spending by 8.2 per cent next year. Japan’s new Prime Minister Sanae Takaichi has already stated that Japan will hit a 2 per cent of GDP defence spending target early. 

The US is therefore pursuing a balancing act. On the one hand, it is encouraging hasty defence build-ups in countries that could help deter China. On the other hand, the US risks inadvertently bolstering China’s claim to be a more stable regional presence. 

The evidence from Trump’s latest tour of Asia is that this US approach to the region is working but at a cost – and that the US administration risks drawing the wrong lessons around using local partners and allies to balance China’s regional presence. 

Fleeting visits

Trump used his visit to the ASEAN Summit in Kuala Lumpur to preside over the signing of a joint declaration involving the prime ministers of Thailand and Cambodia, whose armed forces briefly fought each other in July. Trump wanted to call this a peace agreement but the Thai foreign minister was more circumspect, calling it ‘a pathway to peace’. Trump left before the ASEAN summit itself, ceding the diplomatic ground to Chinese Premier Li Qiang, who addressed the gathering. 

The medium-term outlook points to an uncertain future, including continuing uncertainty over how the US will develop its role in Asia.  

US Defence Secretary Pete Hegseth also attended the ASEAN Summit and used the opportunity to sign a 10-year defence framework agreement between the US and India, with Indian counterpart Rajnath Singh – confirming that for the US, bilateral defence diplomacy is its primary short-term rationale for engaging countries in Asia.

Trump travelled on to Japan to meet new Prime Minister Sanae Takaichi. Takaichi secured a warm response from Trump after burnishing Japan’s credentials in growing its defence sector.

The final stop on the president’s itinerary was Gyeongju in South Korea, host city to this year’s APEC summit. There, he met President Lee and notably gave his blessing for South Korea procuring nuclear powered submarines for the first time, with the vessels to be built in US shipyards. 

Trump skipped much of the summit that followed, though he did meet Xi Jinping, to stabilize the deterioration in US–China relations, and announce a ‘trade war truce’. That included a pledge by China to withhold export controls on rare earths for a year. The likely scenario is the persistence of ‘a cycle of escalation and de-escalation’ in the US–China rivalry. 

Asian states will breathe a sigh of relief over the truce, and the level of US engagement in Asia on display during Trump’s visit. But the medium-term outlook points to an uncertain future, including continuing uncertainty over how the US will develop its role in Asia.  

Will Asia feature prominently in the forthcoming US National Defence Strategy? 

The forthcoming US National Defence Strategy (NDS) could assuage some of this uncertainty – or heighten it. The NDS is expected to reorient some US military attention towards the ‘America First’ objectives of defending the homeland and prioritizing the Western Hemisphere. Recent US unilateral military action against alleged drug boats, and the deployment of a US aircraft carrier battlegroup to pressure Venezuela’s government, indicate what this might entail. 

Regions that could see a reduction of US military presence include Europe and the Middle East. Where Asia fits into this picture remains uncertain. According to a US Department of War statement in May, ‘the NDS will prioritize defence of the US homeland, including America’s skies and borders, and deterring China in the Indo-Pacific’. 

Getting Asian allies to pay more for their own defence is expected be an enduring aim. Elbridge Colby, a leading architect of the NDS, has long advocated such a burden-sharing approach. The theme featured prominently in his book Strategy of Denial, where it was articulated as pursuing an ‘anti-hegemonic coalition’ against China’s long-term aim to establish regional hegemony. 

This was the first visit by a US president to Asia since Joe Biden’s trips in 2023. In the time that has elapsed, China has boosted its reputation among key Asian states.

Turning this into a source of trust rather than uncertainty for Asian countries will be difficult. One key challenge is that there is no alliance structure in Asia that resembles NATO. The US remains the sole lynchpin linking a disparate group of countries. Each has a different view of China – and several do not view Beijing as an existential threat to the region or as their prime security concern.  

—

Speaking at Chatham House, Senior Minister of Singapore, Lee Hsien Loong, reflects on diverging global opinions about China.

That lack of a formal defensive alliance also increases the possibility of disagreements between key US Asian partners – even those that also regard Beijing as a security threat, such as Japan and South Korea.

Takaichi is expected to have a tougher time than her immediate predecessors maintaining relations with Seoul, having previously visited the controversial Yasukuni shrine, which commemorates Japan’s Second World War veterans. Among those commemorated are several former Japanese leaders convicted of war crimes in South Korea, and were Takaichi or a member of her cabinet to visit again it could do serious damage to the bilateral relationship. 

Whether Trump’s trip to Asia is a prelude to more active US diplomacy in the region remains to be seen. This was the first visit by a US president to Asia since Joe Biden’s trips in 2023, when he visited Vietnam, India and Japan for the G7 meeting. Since then, Asia has fallen through the cracks in the travel itineraries of US presidents. 

In the time that has elapsed, China has boosted its reputation among key Asian states, taking advantage of US missteps. China has presented itself as a paragon of stability as a trade and investment partner in contrast to the US’s aggressive new trade policy. Xi toured Southeast Asia in April, seeking to improve relations with countries hard hit by US tariffs, including Vietnam, Cambodia and Malaysia – after criticizing the US and calling for a ‘return to the right path of mutual respect’. 

In the meantime, the US is continuing to impose tariffs, while also asking for greater defence spending by its key allies. It is far from a given that Asia will remain receptive to these messages.