Katarina Barley has an idea for how to make a European army work | Alexander Koerner/Getty Images German minister wants a European (Parliament) army Katarina Barley calls for greater military cooperation, if there are appropriate checks in place.

BERLIN — Katarina Barley has an idea for how to make a European army work: Hand control over to the European Parliament.

Barley, Germany's justice minister and lead candidate of her Social Democratic Party in the European election, told POLITICO in an interview that she would "insist" that a European army "be bound to the vote of the European Parliament."

"In German we call this a Parlamentsarmee," she said, referring to the system whereby no German soldier can be deployed without the Bundestag's consent. Barley said that establishing similar structures in the EU "would require a proper defense committee in the European Parliament.”

Barley's proposal is an ambitious contribution to a debate that so far hasn't gotten much past slogans. Calls for a European army have been in the arsenal of Commission President Jean-Claude Juncker for years, and have recently been echoed by both French President Emmanuel Macron and German Chancellor Angela Merkel.

But little detail was ever added in terms of the common characteristics of an army and its chain of command.

Barley's enthusiasm for a European army is unusual given that the SPD has had a difficult relationship with all things military.

"We are ready for the next step, eyeing a European army," Barley said.

"A European commissioner for defense, a directorate general for defense and European military headquarters would be feasible steps towards this aim of a common European army,” Barley said — but warned against getting the sequencing wrong.

"I wouldn’t start with a DG defense," she said, urging the EU to "take a substantial decision in which direction we want to move" first.

Barley added that it is vital to build on the experience of military cooperation among EU countries, such as a Franco-German brigade or a Dutch-German tank battalion, as well as on recent moves toward converging military capabilities of EU member countries such as the Permanent Structured Cooperation (PESCO) and European Defense Fund (EDF).

EU countries have launched 34 PESCO projects, from common production of a Eurodrone (which is supposed to be ready in 2025) to the launch of a European spy school.

Barley's enthusiasm for a European army is unusual given that the SPD has had a difficult relationship with all things military and campaigned in the 2017 national election against raising defense spending to 2 percent, which NATO members agreed to do by 2024 (as Donald Trump keeps reminding them).

Last month, the Berlin SPD called for the army to be banned from visiting schools. Barley's party colleagues in the German capital described such visits as "military propaganda" and "trivialization of the real dangers of a military operation."

But for Barley, a future EU army could be a way to reconcile the electorate with the military. "One of the main benefits of the European Union is peace," she said, adding that "a common European army would be the ultimate step to ensure that Europeans never wage wars against each other again."

Barley, a dual German and British citizen, said she decided to stand in the European Parliament election because she is concerned about growing nationalism. "The situation in the EU has become worse, seeing the chaos around Brexit and the situation of some member countries. This election will be decisive, we need strong social democracy in the EU to hold this Continent together instead of pushing for national egoisms," she said.

The SPD’s approval ratings have plummeted over the past year, falling to below 20 percent in the polls (POLITICO's polling has the SPD winning 15 percent of the vote in May's European election). But Barley believes she can help her party do better.

Barley rejected a suggestion that her party leader Andrea Nahles offered her a Commission top job if she ran in the election. Asked whether she would accept an offer to become a commissioner, Barley replied: "This is not the time for this kind of question. I will do my campaign and then see what the outcome will be."