A potential Trump-Vance victory in the November 2024 US elections would signal a geopolitical reckoning for Europe. With escalating conflicts in the Middle East and systemic shifts in the balance of power underway in the Indo-Pacific, Europe must again confront an uncomfortable truth: its days at the centre of global power are over. In this new multipolar world, Europe must learn to engage with shifting U.S. foreign policy priorities. And nowhere are the differences in foreign policy and alliance management more starkly apparent than in the U.S. Republican Party. As election season brings elite opinions into sharper focus, European leaders would do well to study the foreign policy rationales of three key factions within the Republican Party: traditional internationalists, hawkish activist hardliners, and neo-isolationists.

While these three Republican factions remain united in preserving America’s free hand on the international stage, the subtle differences in how they approach this task matter to European leaders. Two key differences that matter most: first, the order of foreign policy priorities, in other words, what their key objectives are, and second, how they go about achieving those objectives.

To begin with, European policymakers must familiarise themselves with the approach of Republican internationalists. This group is traditionally pro-interventionist and relatively hospitable to European interests. However, with the Trump-Vance ticket holding the Republican party in its orbit, pro-European Republican elites are beginning to recognise the need to balance out NATO burden-sharing with Europe. Archetypal Republican internationalist Nikki Haley, admitted in early February 2024 that while she regards NATO as the most successful organisation in the past 75 years, she is nonetheless “all for making NATO pay their fair share”.

Along with many U.S. foreign policy establishment elites, this faction perceives China as the number one threat to the U.S. and its interests. As a close second, Russia and Iran remain regional strategic priorities. For Europe, the U.S. elites’ focus on China is nothing new, however, with its defence capabilities under scrutiny, the message from the internationalist corner is clear “European allies need to pull their weight because we are stronger together”.

While Republican internationalists may be privy to the need for a more capable transatlantic ally, European policymakers can take comfort in how this faction approaches alliance management. For now, conservative internationalists, true to their name, are still globally oriented, willing to maintain a forward presence in Europe and nurture American leadership around the globe, including via multilateral fora. European allies are perceived as necessary and worth nurturing over the long term. Nevertheless, European leaders would be well advised to re-iterate why Europe is a good and natural ally as a starting position under any future Republican internationalist administration. Failing this, Europe runs the risk of further alienating itself from a powerful group of Republican elites.

Next, Europe must contend with the worldview of Republican activist hardliners. This group includes the likes of former Vice President Mike Pence who takes from the thinking of Trump’s former National Security Advisor John Bolton and hails from a more idealistic, yet intensely hawkish approach to foreign affairs and security. Activist hardliner’sforeign policy priorities remain largely in line with their internationalist counterparts: China dominates the priority list, while pro-NATO sentiment remains strong. Republicans in this faction are more willing to take a hardline approach to China economically. Their hawkish tendency to re-prioritize rogue actors like North Korea or Iran – alongside Russia and China as part of a connected threat facing America and its allies is unsurprising and indeed nothing new. For activist hardliners, America’s task is now to counter this new “axis of evil” in every theatre – including in Ukraine. Their message to Europeans is similar to their internationalist counterparts: “Get your act together now, because we need to work together against the same threats”.

Yet, how activist hardliners approach their objectives is unsettling for European interests. This faction is partial to unilateral action over multilateral dialogue, preferring strength through force and red lines over restraint. Europeans can, however, remain thankful for this faction’s willingness to honour its defence commitments in the shape of NATO’s Article 5. However, if Europe wants to show this faction they mean business, current arrangements in burden-sharing will need to be revisited. Under an activist hardliner administration – Europe would need to adopt a far more assertive stance. In this scenario, Europe would need to psychologically and physically ‘join’ the U.S. in the Indo-Pacific, make hard decisions about trade with China, implement tough sanctions on Iran and build defence partnerships with like-minded governments in the region.

Finally, and perhaps most critically, Europe must confront the neo-isolationists within the Republican Party. Characters like J.D. Vance and Matt Gaetz often harbour more isolationist foreign policy objectives than Trump himself. Vice-presidential nominee J.D. Vance has repeatedly stated his opposition to U.S. funding for Ukraine, asking why these arms aren’t being sent to Taiwan instead. Iran and North Korea follow closely in the order of priorities for this faction, while Russia would ideally become Europe’s geopolitical responsibility in a more transactional approach to international relations. The message from this faction has been consistent: “Get your act together quickly, or else”.

For Europe, a neo-isolationist administration represents the most uncomfortable scenario. Neo-isolationists tend to pursue their goals unilaterally, often disregarding traditional alliances. European foreign policy elites, still believing that shared values underpin the transatlantic alliance, will need to pivot towards a form of pragmatic realism while recognising that wider geostrategic challenges emanating from China are the new priority. Because, for the neo-isolationists, the real glue in any future transatlantic partnership is Europe’s willingness to compromise on China and help keep Russia at bay – even without direct U.S. support. Here, Europe will need to show guts and stand by principles, while also showing that it can support the U.S. in taking a firmer stance on defending Taiwan and getting tough on Iran.

All three Republican factions signal tough economic and security realities for Europe. Economically, Europe should brace for higher tariffs to achieve a balance of trade more favourable to Washington. On defence, Europe should also expect less U.S. support for Ukraine and more pressure to increase capabilities beyond NATO’s 2% of GDP benchmark and strike its strategic deals independently. European leaders would be wise to prepare in advance, and not bet too heavily on a Harris-Walz win this November.

Europe has already begun its homework, but it’s not being done fast enough. Without carefully gaming out each one of these three possible GOP factions as potential negotiating counterparts, Europeans will be left scrambling when the time comes to face hard questions from its transatlantic ally. Europe must be ready to adapt to changing expectations from all three competing Republican foreign policy schools or face the geostrategic consequences.

Further Reading on E-International Relations

• The Day after Tomorrow: The EU and the Iran Nuclear Deal
• Trump’s Foreign Policy Doctrine of Uncertainty
• Trump’s Foreign Policy Mantra: ‘Whoever Pays For It!’
• Opinion – Nationalism and Trump’s Response to Covid-19
• Opinion – Bad Omens for America after Liz Cheney’s Defeat
• Opinion – Ukraine and the Republican Party’s Drift from the ‘Honor Code’ of Jacksonian Diplomacy