ON NOVEMBER 23rd Mark Rutte, the new head of NATO, and Donald Trump, America’s president-elect, were photographed together grinning delightedly and shaking hands in Palm Beach, Florida. Yet the mood in Europe’s defence ministries is one of grim foreboding. At a gathering of defence officials and defence-industry executives in Prague a few days after the election, the most optimistic sentiment was that Mr Trump was “unpredictable”. Others were a lot less upbeat.