The same can be said for the Ukraine conflict. What was once a situation poised on the knife-edge of open war has, thanks to Ms. Merkel and Mr. Hollande, moved from the military playing field to the diplomatic arena. The United States, which was at first skeptical of their Minsk agreement, has quickly put its full weight behind the deal. Russia has been checked, giving Ukraine the opportunity to build a stronger state that can resist Russian attempts to bring it back in its sphere of control. Again, the union was tested, and it became stronger.

Perhaps no challenge better illustrates the union’s strengths than the waves of refugees arriving in Europe. Ms. Merkel has correctly framed it as a challenge for Europe as a whole, rather than for individual countries. And Europe has acted accordingly, taking a contentious but successful vote to spread the burden of accepting the refugees.

True, the old refugee system broke down under the sudden weight. But with a speed that surprised even Euro-optimists, the union has begun to fashion new rules, often on the fly.

What we see unfolding is a pan-European system of governance. It’s not always pretty. But that shouldn’t come as a surprise when 28 countries with different histories have to compromise on vital issues, and quickly.

The new European Union is redefining the role of the nation state without replacing it. The new European Union is overwhelmingly intergovernmental, built around cooperation among nation states. It is based on deal making, with the German chancellor as the power broker at the center. It deals with issues that have long been seen as internal affairs, at the heart of sovereignty such as currency, security and borders.

And while in the past the European Union was built and administered by bureaucrats, largely hidden from the public, the new union is deeply political. The time of backdoor deals in Brussels is over.

While centrifugal forces still threaten the European project, it seems that the center does in fact hold, for one simple reason. Member states ultimately feel that they get as much as they give: a framework that helps them to tackle the challenges of globalization.