As the current US President challenges the post-war status quo on the American alliance system, Congress is increasingly stepping up as one of its most vocal defenders. While there are limits to how far Congress would challenge the President and how much difference this would make, cultivating closer congressional ties represents a useful opportunity for allies seeking stability in America’s alliance management.

America’s traditional European and Asian allies have been dismayed by the President’s challenging of the alliance system. While past presidents have had disagreements with allies over defence spending, security commitments, trade and the use of force, President Trump’s questioning of the fundamental value of alliances and the national interests they serve, represents a significant shift from the post-war consensus in Washington. “America First” portrays allies as taking advantage of the US, judges the burdens of alliances to be greater than the benefits and prefers more transactional relationships. Allies are increasingly concerned that the President’s anti-alliance outlook may not be an aberration and that business-as-usual will not resume after his term.

Yet for now, the day-to-day management of alliances goes on and Congress has increasingly stepped in to fill the President’s void by supporting alliances. The US Constitution grants foreign policy powers to both the executive and legislative branches, with the system designed as an “invitation to struggle.” Article I outlines Congress’ powers over trade, declarations of war, approval of presidential appointments, treaty ratifications and oversight of departments, as well as their control over the budget. Most foreign affairs-minded congressional members tend to subscribe to the traditional view of America’s alliances and recently have come their defence.

For example, Congress differs from the President over its support for NATO. Pre-empting the President’s visit to the July NATO summit in Brussels, the Senate overwhelmingly passed a bipartisan resolution expressing support for NATO. The NATO Observer Group was relaunched in early 2018 and saw its Senate membership increase after the contentious Brussels summit; with its Republican leaders voicing that Congress had the means and will to prevent the President from withdrawing the US from NATO. In August, twenty senators organised a private meeting with NATO officials and European diplomats to reassure them of Congress’ commitment to NATO and downplay the President’s behaviour. While the President has not indicated that he will soften his criticism of NATO, Congress’ support for the alliance system and their increasing willingness to get involved in foreign relations would be useful for allies seeking to prevent the President from taking drastic action, such as withdrawing from security treaties.

Australia has long recognised the value of cultivating relationships with Congress, using diplomatic lobbying as a tool to build connections, gain information and advocate for Australia’s interests. Establishing its “own in-house lobbying firm” called the Congressional Liaison Office, the embassy’s congressional outreach has delivered tangible results, including the passing of the Australia-US Free Trade Agreement and E3 visa. The aftermath of the tense Turnbull-Trump phone call illustrated the benefits of these efforts, as more than sixty members of Congress reached out to Australia’s ambassador to express their support for the alliance. Resolutions reaffirming the alliance were passed by both houses and a bipartisan “Friends of Australia” caucus was launched. This congressional pressure contributed to the President’s shift towards a friendlier approach to Australia — seen in its exemption from steel tariffs — and suggests that in some cases, Congress can act as a moderating force on Trump’s alliance management.

Ultimately however, the President has the most significant power and influence over US foreign policy, including alliance management. In recent decades, Congress has tended to defer to the executive on foreign policy. In some cases, their obstruction of international agreements – for example the UN Convention on the Law of the Sea – undermines allied cooperation and their interests in a “rules-based order.”

Furthermore, the domestic political climate also limits Congress’ willingness to moderate the President’s anti-alliance leanings. Both parties generally opposed the President’s initial decision to not exempt allies from tariffs and the chairman of the Senate Foreign Relations Committee drafted legislation which would have made congressional approval for national-security tariffs a legal requirement. Yet despite bipartisan support, the Republican Senate leadership has not allowed this to be brought to a vote. This raises the issue that while Congress disagrees with the President over his treatment of allies and has made efforts to improve relations themselves, domestic political concerns mean that they have largely fallen short of using their constitutional foreign policy powers to overtly challenge the President outside of symbolic motions and rhetoric. The upcoming midterm elections may only intensify Congress’ dysfunction and partisanship, leaving allies’ interests on the periphery.

While allies cannot solely rely on Congress, increasing congressional engagement would be a useful way to cope with President Trump. Yet they cannot ignore the President, and while Congress may restrain him from withdrawing the US from its alliances, his words and actions still damage allies’ confidence in US commitments. Though allies are not decoupling from the US anytime soon, concerns about the possibility of longer-term anti-alliance sentiment in the US may force allies to reflect on and reconfigure their own strategies.

Vicki Sideris is conducting an internship with the Australian Institute of International Affairs NSW. She is currently in her third year of a Bachelor of Commerce (International Studies), studying International Relations and International Business at the University of New South Wales. In 2017 and 2018, she spent a year studying at Georgetown University in Washington, DC. She has previously worked as a project consultant at the Social Impact Hub and as a contract administrator at Insurance Australia Group. Her main areas of interest include American and Japanese foreign policy and domestic politics and Indo-Pacific trade and security.