The Republican party is jubilant. Since President Joe Biden’s poor performance in the televised presential candidate debate, and subsequent apparent cognitive lapses, including at the NATO Summit press conference, Donald Trump’s re-election is looking increasingly likely. Now, following last Saturday’s assassination attempt, Trump has a new opportunity to cast himself as a courageous leader willing to sacrifice his life for America, which the Republican party will hope can attract voters from beyond the target base.

One segment of the party’s foreign policy crowd is particularly euphoric. Trump’s announcement that J.D. Vance is his choice for vice presidential candidate has fired up one of the Republican party’s three foreign policy tribes, the prioritisers, which include the influential Heritage Foundation think-tank and Trump’s former Pentagon official, Elbridge Colby. This tribe has long argued that global overstretch by the US military weakens its capacity to deter China from invading Taiwan, and sees the United States’ prioritising of arms supplies for Ukraine to blame for the $19 billion backlog of weapon deliveries to Taiwan. They are in strong disagreement with the primacists of the party, such as Nikki Haley, Mitch McConnell, and Lindsey Graham, who claim America can fight several wars at the same time and should simply increase military spending. Conversely, prioritisers feel that this should fall to wealthy European countries. Meanwhile the restrainers of the party, including Senators Rand Paul and Mike Lee, feel that the US should reduce its global military commitments altogether.   

Vance is therefore the perfect envoy for the prioritiser argument: he was the first senator to bluntly describe European countries as American “client states”, and to call for change in the hierarchy between Europe and America through stronger European capabilities. “America does not need clients, it needs allies,” wrote Vance after the Munich Security Conference. He has repeatedly argued that wealthy European nations such as Germany should defend Ukraine without US assistance, that US resources are limited, and that America’s provision of aid to Ukraine is directly hindering its successful deterrence of China in Taiwan. Now Vance’s nomination has secured the prioritisers their own entrance ticket to the White House – should Trump win the election, of course.

But, while a potential second Trump administration might be dominated by this faction, there is no indication that Trump himself is in alignment. In fact, Trump’s views on China remain erratic and unpredictable. During his time as US president, and even now as the Republican presidential candidate, Trump has shown restrainer tendences. He has refused to confirm if he would defend Taiwan in the event of China using military force to secure reunification, and has accused Taiwan of stealing America’s advantage in semiconductor technology. He recently defied the majority of his party on legislation that requires TikTok to divest from Chinese ownership, or face a ban in US. The Congressional Oversight Committee report shows that China spent millions of dollars in Trump Organization entities during his previous stint in office.

Trump’s current China policy is focused on imposing high tariffs – up to 60 per cent, according to the Trump 47 Agenda – on the import of Chinese goods. This demonstrates his obsession with the trade deficit, and indicates that he may try to reach a trade deal while making some concessions on semiconductor technology, or Taiwan. Such a move would go directly against the prioritisers’ Taiwan policy, and against the Republican consensus that integrated deterrence of China requires doubling down on economic security measures.

Divisions between Trump and his administration are nothing new. During his first term, his primacist cabinet and Congress often undermined his deal-making, for instance regarding the delivery of 100 F-35 fighter jets to Turkey. However, it remains to be seen whether the prioritisers participating in Project 2025 – which claims total loyalty to implementing Trump’s policies – can still inhibit some of his deal-making inclinations, or push him to overcome his hesitations. Indeed, Trump losing the battle over TikTok in Congress suggests that Trump can only deviate so far from the existing Republican consensus on China.

However the rift between Trump and his administration on China and Taiwan play out, it is not good news for Europe. Decisions from a prioritiser cabinet, or a more erratic Trump himself, will leave Europeans facing a huge dilemma when it comes to the US-China rivalry. A future prioritiser administration will likely expect Europeans to take decisive action on technology and export controls, inbound and outbound investment screening, supply-chain resilience policies, and cybersecurity measures in relation to China. And they will expect the European Union – and especially Germany – to address the issue of Huawei’s presence in its critical infrastructure.

On the other hand, a Trump presidency will likely escalate tariffs on both China and Europe, via a universal baseline tariff of 10 per cent on all US imports. This will entail some hard choices for European governments, which could face US pressure to implement economic security policies and risk Chinese retaliation and might find itself in a trade war with the US. Additionally, Vance and his advisors are likely to double down on Trump’s view that US assistance to Ukraine, as well as its contribution to overall European security, should be backfilled by wealthy European nations.

A prioritiser administration could therefore mean a drastic reduction of US resources for Ukraine, and an overall compromising of European security, irrespective of potential disagreements on Taiwan and China policy. A Trump and Vance alliance will almost certainly impact European security as well as the European economy – but while the EU single market still represents a source of leverage, security remains Europe’s greatest vulnerability. The EU may struggle to respond effectively as it attempts to overcome the problem of collective action at the supranational level, and some member states will find it difficult to meet defence spending targets due to their fiscal constraints. Therefore, rejuvenating the EU’s role in supplying funds for defence, such as former European Commissioner for Internal Market Thierry Breton’s proposal to raise €100 billion in bonds to finance defence expenditure, should be back on the table. Similarly, Ursula von den Leyen should lead on China and trade. Her track record on China may buy her some credit with Republican prioritisers, while the EU’s exclusive competence over trade policy may help her negotiate exemptions from a universal baseline tariff and avert a US-EU trade war. If there is one silver lining of a prioritiser administration, it is that Vance and his allies must accept that the US needs a strong Europe to effectively contain China.