When Donald Trump takes office on 20 January 2025, he will face no greater foreign policy challenge than rising China’s challenge to the US economy and to US security in East Asia. How he manages this challenge will likely determine the course of US foreign policy for many decades.

Trump made many campaign promises. But he promised all things to all people to get elected. A similar political expedience could lead him to renege on his campaign promises. Moreover, Trump does not have a strategic vision for the US. Rather, he focuses on policies on a case-by-case basis that reflects his confidence in superior US power to achieve his objectives. The one certainty of the Trump presidency is that there will be great uncertainty.

There is no greater uncertainty than how Trump will manage relations with China and its challenge to US interests. First, China’s economic growth is the foundation of its military challenge to US security in Asia. Second, its development of advanced technologies contributes to its military and to its ability to shape global economic development. Third, its economic growth challenges the US’s leadership of the global economy. And, fourth, its inexpensive and high-quality exports weaken the US industrial base.

Trump promised that he would impose 60% or higher tariffs on Chinese exports to the US. He promised similar tariffs on Chinese products manufactured in third countries and then re-exported to the US, including a 200% tariff on Chinese automobiles manufactured in Mexico. Such tariffs could cause a spiralling trade war. They would also challenge the global economy, as protectionism would spread in response to the surge of US and Chinese exports to other countries.

But increased tariffs would contribute to renewed inflation in the US, as the cost of tariffs would be passed on to the prices paid by the American consumer. Trump understands that inflation was the major weakness of Kamala Harris’s presidential campaign. He would not want inflation to hobble his own presidency. Second, Chinese retaliatory tariffs would contribute to reduced US exports to China, the third largest US export market, contributing to US financial losses and unemployment in important sectors of the US economy.

As during his first term, Trump may continue to believe that the threat of additional tariffs will compel China to agree to a trade agreement that would commit it to reducing its trade imbalance with the US. A new agreement would allow Trump to claim victory, while avoiding the punishing costs of high tariffs. Trump’s close relationship with Elon Musk could also persuade Trump to avoid an escalation of the trade war. China is the largest market for Musk’s Tesla automobiles. To protect his investments in China, Musk could advise Trump to negotiate with China, rather than unilaterally impose steep tariffs.

In negotiations with China, Trump could agree to moderate Biden policy on technology transfers to China, limiting constraints on technology cooperation to those technologies with national security implications. And in a quid pro quo for a Chinese commitment to reduce the trade imbalance, he could also agree to less restrictions on Chinese investments in the US, following EU policy that blocks Chinese export of electric vehicles, but encourages their production in its countries.

Trump must also contend with China’s challenge to American security in East Asia. The rapid growth of China’s navy and the emergence of regional bipolarity have led many US security partners to increase security cooperation with China. In response, the Biden administration expanded US military presence, gaining access to five additional Philippine bases, including bases fronting the Taiwan Strait, and it expanded defence cooperation with South Korea and Taiwan. It also increased the frequency of its freedom of navigation exercises in the South China Sea and US naval transits through the Taiwan Strait.

Trump has developed a personal resentment toward China’s resistance to cooperation with his overtures during his first term as president. He rankles at China’s challenge to “American greatness”. This suggests that he would resist compromise with China regarding Taiwan and that he would sustain US military pressure on China in East Asia. It also suggests that he could increase US military involvement in the region’s maritime disputes.

Nonetheless, Trump stresses “America first”. He has criticised excessive US intervention in international conflicts, such as in Ukraine. Given his “neo-isolationist” inclinations, he may conclude that US involvement in the East Asian security and territorial disputes unnecessarily raises the risk of war with China and imposes significant financial burdens on the US economy.

Moreover, Trump has dismissed the contributions of smaller countries to US interests and he questions the value of US support for their security. Thus, just as he is critical of the NATO countries’ alleged free riding on the US, he may reconsider the US defence commitments to US security partners in East Asia.

Trump’s criticism of Taiwan’s alleged theft of US technologies and his insistence that Taiwan defence budget should be 10% of its GDP suggests he could reconsider the Biden administration’s policy of increased military assistance to Taiwan and its uncompromising support for Taiwan’s diplomacy. Similarly, he may reevaluate US involvement in the China-Philippine dispute over South China Sea shoals and reefs and growing US military presence in the Philippines. His insistence of his close relationship with Kim Jong-un may encourage him to restrain US defence support for South Korea.

During Trump’s first term, the primary focus of US security policy in Asia was the Quadrilateral Security Dialogue (Quad) countries and the Indo-Pacific defence strategy. Rather than seeking to bolster US military presence inside East Asia, this approach focused on enhanced defence cooperation with India, Australia and Japan, and a greater US naval presence in the Indian Ocean and the West Pacific. Trump 2.0 may well return to this strategy, at the expense of US security commitments inside East Asia.

US strategic uncertainty will necessarily diminish regional confidence that the US will balance the rise of China. It will thus diminish confidence in the US as a reliable security partner. Unsure of US commitment to East Asia, countries will reconsider their alignment strategies and could move toward greater equidistance between China and the US.

The only certainty of Trump 2.0’s China policy is uncertainty. Trump could double down on US protectionism and resistance to the rise of Chinese regional influence. But he could also seek to deescalate conflict with China in the interest of domestic economic stability and to focus on his “America first” agenda. Whatever he decides, US uncertainty will compel many countries in East Asia to reevaluate their response to the rise of China and the US-China competition.