Marcel van den Bergh/Hollandse Hoogte/Redux

Later this year, the leaders of European Union nations will meet in Brussels for their annual European council. On the agenda: a discussion of Europe’s military might. At the summit, it’s likely that two equally bold visions for European defence will be put forward. One would see the union’s 27 member states pool military resources as never before—with an eye to eventually building a bona fide EU army. The other would see the union member with the strongest military, Britain, withdraw from the EU—leaving the Continent sputtering.

In London, it is talk of a potential pullout from the EU that dominates. But elsewhere, calls for a pan-European military are growing—with France and Germany leading the charge. In September, a group of EU foreign ministers spelled it out directly, weighing, in a controversial report, the possibility of a European army.

How exactly that army would function has yet to be decided—or even sketched out in much detail. In the event of another Iraq war, would the EU commit troops as a block? In the case of a major terrorist attack in Paris, would EU troops be called in? What seems unlikely is the prospect of EU leaders disbanding their own militaries. For that reason, a viable EU army would have to accommodate coexisting national forces—and leave room for individual opt-outs. But the question is: should the balance between national and continental defence be shifted? And how far? Last fall, EU defence ministers agreed to develop what sounds an awful lot like a kindergarten rulebook: a voluntary code of conduct on pooling and sharing. Continue…