The war in Ukraine reminds us what the EU is for. But even bigger challenges lie ahead | Timothy Garton Ash

Support for the European Union is strong - even in post-Brexit Britain. Can it come through its external battles, too?

It's springtime in Brussels and the European Union has a spring in its step. Its leaders and institutions have been galvanised by the war in Ukraine. The war has reminded us what Europe is really about," people kept telling me on a recent visit to the EU's capital.

There's a popular theory that says European integration advances through crises. The truth is that sometimes it does and sometimes it doesn't. You'd have to be a starry-eyed Euro-optimist, for example, to claim that European unity was really advanced by the 2015-16 refugee crisis. But in its last two big ones, the Covid pandemic and the war in Ukraine, we have seen the challenge and response" mechanism that the historian Arnold Toynbee identified as one of the patterns of history.