Why would a US election win for Trump cause concern in Europe?

With voting underway on Tuesday in the knife-edge US presidential election, there is concern in Europe that a Donald Trump victory could spell trouble for the EU on matters from security and aid for Ukraine to trade tariffs, according to analysts.

While Democratic candidate and Vice President Kamala Harris is seen as likely to maintain the status quo with the EU on such issues, Republican former President Trump has repeatedly criticised the bloc and threatened to upend current EU-US ties.

Aid for Ukraine following Russia's full-scale invasion in February 2022 will be one of the most urgent talking points between the EU and the next US president.

Washington has given Kyiv tens of billions of dollars in military and financial assistance since 2022.

However, Republicans are increasingly divided on providing more money to Ukraine while Trump has repeatedly criticised Ukrainian President Volodymyr Zelenskyy and refused to back a victory for Kyiv, suggesting that he could wind down US support if he were to win the election.

“One scenario is that Trump would cut off the weapons supplies to Ukraine," Bart Szewczyk, an analyst at the German Marshall Fund, told Euronews in an interview.

Trump has also said he could end the conflict, if elected, before he takes office in January, but without explaining how or giving any details.

Szewczyk said he may look to strike a deal with Russian President Vladimir Putin to bring about a ceasefire and end the war "over the heads of the Ukrainians and Europeans".

A more likely outcome is that a Trump administration would continue to deliver weapons to Kyiv but ask Europe to foot the bill. Overall EU support to the Ukrainian army is estimated at €43.5 billion currently, according to data from the bloc, but this could rise to more than €200 billion if such a scenario became a reality, Szewczyk said.

Alternatively, he warned there is likely to be “chaos, a mishmash of attempts at a peace deal, continued weapons supplies, stop-start and so forth without any rhyme or reason".

'America first'

Trump has long championed US isolationism - a stance that has grown in popularity within the Republican Party in recent years.

At a campaign rally in February, he said he would not defend NATO members from an attack by Russia if they failed to meet their spending obligations on defence.

The US is frustrated that many of NATO's 31 members are not meeting an annual defence spending target of at least 2% of GDP. The military alliance estimates that 23 members will meet the goal this year, up from just three nations a decade ago.

Washington currently pays about 16.2% of NATO's principal budgets, the same share as Berlin contributes.

"The idea is that Europe must really prepare a world in which the US will no longer play the role it has today," Serge Jaumain, a professor at the Université libre de Bruxelles (ULB), told Euronews.

This could be the case under either a Trump or Harris administration, Jaumain said, noting that the era of the US being "extremely present at the European level" was over.

Protectionism back in fashion?

Another cause for concern in Europe is the threat of Trump implementing protectionist policy and hitting other countries with trade tariffs. He has vowed to impose 10% tariffs on imports from all nations, and 60% duties on imports from China.

The US is the EU’s main trading partner. Trade in goods between the partners has more than doubled over the last decade, totalling nearly €870 billion in 2022, according to the latest data from the bloc. The three main EU exports to the US are medicines, pharmaceuticals and vehicles, while natural gas, petroleum oils and crude oil are the biggest EU imports from the US.

Yet Trump has been critical of the EU, warning that it would "pay a big price" for not buying enough American goods if he won the election.

“In terms of trade relations, the idea is to protect the US everywhere," Jaumain said. "These measures (the proposed tariffs) are also possibly in retaliation against Europe.”

Nevertheless, given the unpredictability of the Republican candidate, such campaign promises must be viewed with due scepticism, according to analysts such as Jaumain.