Germans are preparing to commemorate the 25th anniversary of the breaching of the Berlin Wall, on November 9th 1989. This weekend there will be events throughout Germany, divided during the Cold War by a 155km system of barriers. But Berlin, the western part of which was encircled by the wall, is the focus. Where once East Germans were shot for trying to escape (and a few succeeded), thousands of light balloons will trace the old border on Sunday night. Germans will contemplate how far they have, and still have not, grown together: the former East Germany, for all its bright spots, remains poorer. They will also ponder their reunited nation’s role. Other European countries that once feared German power increasingly demand German leadership, in crises from the euro zone to Ukraine. But there is no consensus in Germany on how far its clout should extend beyond economics to include diplomacy—or even warfare.