Long before last month's EU parliamentary elections, the bloc's 28 member states had agreed that they would take the outcome of the popular vote into consideration when nominating the next European Commission president.
But the candidate from the leading European People's Party, Jean-Claude Juncker, has proven divisive among the EU's national leaders. British Prime Minister David Cameron has reportedly warned his continental counterparts that Juncker, a committed European federalist, would undermine already waning public support for EU membership in the euro-skeptic UK. Finland, France, Hungary, the Netherlands and Sweden have also reportedly expressed reservations about Juncker.
"The US very clearly favors the UK obvously remaining within the European Union and being a productive member," Erik Brattberg, an analyst with the Atlantic Council, told DW.
"It views a strong European Union as a better partner to deal with, both bilateraly but also in terms of the European Union's ability to have a strong and united foreign policy," he said. "Anything that pushes the UK away from the European Union, from a Washington perspective, would be a bad thing."
At the earliest, the member states will nominate and the European Parliament will confirm the next commission president by the end of July. But given the EU's internal divisions over Juncker, the process of political horse-trading could drag on into the fall, leaving a leadership vacuum in Brussels for much of the rest of the year.
"[… ]Especially at this pivotal moment in the EU's relationship with Russia and regarding Ukraine, there's a risk that this uncertainty will put a hamper on transatlantic relations […]," said Brattberg, who also works with the Center on Transatlantic Relations at John Hopkins University.
Confrontation with Russia
Divisions over the next European Commission president are not the only challenge. Within the European Parliament, euro-skeptic parties have gained ground. France's right-wing National Front (FN) scored a major win in the elections, beating out the country's two establishment parties.
In a recent interview with newsmagazine Der Spiegel, Marine Le Pen said that she admires Vladimir Putin as much as she does Angela Merkel. According to the FN leader, the Russian president stands up for his country's interests and doesn't let foreign powers impose decisions on Moscow.
"Some of these parties, some more than others, very openly have a very favorable view toward Putin and Russia, while others are hosting skepticism and anti-Americanism," Brattberg said. "Those are obviously from an US perspective worrying signs."
In the wake of the Ukraine crisis, the EU has sought to reduce its energy dependence on Russia as it expands eastward. Both goals are strongly supported by Washington. But according to Brattberg, the euro-skeptic parties could play a spoiler role by trying to undermine further EU enlargement and the creation of a more integrated European energy market.
Whether or not these parties manage to organize themselves into an effective parliamentary caucus is an open question. Daniel Hamilton, executive director of the Center for Transatlantic Relations at John Hopkins University, believes that the euro-skeptics and other smaller parties will ultimately have little long-term impact on the policy debate.
"The fractured parties don't have one common message, they also conflict with each other as well, so that will blunt their influence," Hamilton told DW.
He went on to say that it was still possible for the European People's Party and the Progressive Alliance of Socialists and Democrats (S&D) to form a grand coalition. That would create a stable, centrist and pro-transatlantic parliamentary majority.
Transatlantic trade deal
Nevertheless, certain joint EU-US projects are likely to be put on hold for the remainder of the year. With the future makeup of the European Commission uncertain, the ambitious and controversial Transatlantic Trade and Investment Partnership (TTIP) is unlikely to see any major progress in the coming months, according to Hamilton. Populist parties such as the National Front, which are anti-globalist as well, could create obstacles. Prior to the election, Le Pen told the Reuters news agency that she plans to form a coalition within the European Parliament to oppose the transatlantic trade deal.
"This year is a political winter for TTIP because there's no commission until later this year and probably until the end of the year [with] nothing really functioning to make any political trade offs with the United States," Hamilton said. In addition, the European Parliament is likely to demand a deal with Washington on data protection in the wake of the NSA scandal.
But the difficulties lie not just in Europe. The US faces mid-term congressional elections this November. President Barack Obama is pushing for Congress to pass trade promotion authority, which would require Congress to vote up or down on the final TTIP deal as negotiated by the White House, preventing lawmakers from adding amendments.
"It looks like the Republicans are likely to take the majority in the US Senate, which means the Democrats right now are very reluctant to embrace any broad new trade promotion authority, which the president needs to conclude any deal," Hamilton said.