'A splendid concept'

European Commission President Jean-Claude Juncker says the European Union should have its own army to "help shape a common foreign and security policy and to seize together Europe's responsibility in the world."

Deutsche Welle: Why float the idea of a European army now?

Claudia Major: Juncker is using a particular political setting - the Ukraine-Russia crisis - to relaunch an idea that hasn't worked out before: the very old idea of integrating the military forces that goes back to the 1950s and eventually failed in 1954. When the idea, which has an economic and a political dimension, was first launched, there was a different threat perception, but by 1954 the situation had changed, the states felt less threatened and were less willing to engage in a very strong interdependence, and to abandon sovereignty in an area that is very much at the heart of the nations.

The EU's Lisbon Treaty also formally laid down the idea of a joint EU defense force.

The Lisbon Treaty set out to call for a close integration in the military area, yet so far the states have not been active in implementing it.

The German Defense Minister has said she has a view to one day having a European army, so Juncker has backing from the German side - but what about the other EU states?

It's an idea that's typical for German foreign policy DNA - always embedded in the EU, always embedded in alliances, never alone. You can literally look at every coalition treaty over the years and you will always find it. Not surprisingly, countries like the UK or France are not that keen; they fear that such a common construct might inhibit their foreign security capacity.

National armies, with each country purchasing and owning the same kind of hardware, - saving money sounds like a real advantage, but is it a main selling point?

I think that's one selling point; there are several others and in this particular situation, the political dimension is very important, too. Talking about a common army is also talking about a common policy, standing together as a strong political union. That's as important as the money issue.

What do you perceive as the biggest problem?

It's a wonderful idea, but people can have it without worrying it will really be implemented. If you look at what a European army would mean, the most important question is, who decides on sending soldiers where? Who decides on whom they might kill, or who might kill them? Who gives the orders? What parliament decides? What defense industrial base do we have? It's very nice to talk about a European army but eventually you need to discuss the technical details. German laws for soldiers are very different from the French, British, Slovak, Italian and Spanish laws, for instance. So which law applies?

If you don't agree on what our European security principles are, and if you don't see a threat in the same things, you cannot really deploy an army somewhere.

Is giving up sovereignty the biggest stumbling bloc?

If we implemented it, we would save a lot of money, we would gain enormous political weight - just imagine, 28 states putting their armies together, what an immense political power that is -, we would increase military efficiency. But so far the states have not really been keen on giving up sovereignty, or even on taking the necessary steps that might mean changing the law.

What could the next steps be?

In the long term, Europe needs its own army – not an intervention army that proactively wages wars, but a defensive army with crisis management capabilities where Europe can actually live up to its high normative standards. There's an EU defense summit coming up in June, and EU foreign affairs chief Federica Mogherini just launched the process of rewriting a European security strategy. These are elements that could support setting up a European army. We could find a common denominator in what European security policy is. At a defense summit, couldn't we agree on joint European equipment, and a joint European industrial base? Those might be little steps toward the very, very long-term goal of a European army.

Claudia Major is a security expert at the Berlin-based German Institute for International and Security Affairs (SWP)