The US Congress plays an important albeit limited and context-dependent role shaping US foreign policy in Asia. During President Donald Trump’s first two years in office, the Republican-majority Congress appropriated two major increases in defence spending, kept the State Department’s budget stable amidst organisational uncertainty, and maintained a high tempo of Asia-specific foreign policy interventions that represented growing interest in the region among legislators. At the same time, Congress remains a bellwether for international concern about the ability of the US political system to provide the bureaucratic stability on foreign policy that is a precondition of robust engagement in the region.

Over the next two years, Congress will influence Asia-relevant issues of consequence for Australia, including China policy, diplomacy with North Korea, and the size of the defence budget. Congressional action will be shaped by new chairmen on the key Senate and House committees that oversee US foreign relations, armed services and trade. Republican-led Senate committees, under new leaders who are broadly supportive of Trump’s agenda, are likely to be less independent or influential than in the last Congress. However, Democrats’ majority in the House of Representatives will facilitate oversight of and investigations into Trump and heightened scrutiny of Asia policy. Congress’ role will be shaped by deep polarisation that will at times offer the Trump administration a relatively free hand. Conversely, there will also be selective bipartisan push-back when President Trump challenges long-held foreign policy positions.