One day Europeans may thank Mr Donald Trump for forcing them to do what they should have done long ago: reassert their own military and technological independence. For years, Europe’s strategic stance has been to hope for the best and prepare for the best. But the US President’s message could not have been blunter in Davos this week: Europe must now prepare for the worst. Mr Trump may have backed off from military action against Greenland and punitive tariffs against its European supporters, but his mocking antipathy towards Europe was overpowering. It is way beyond time for Europe to absorb that message, rip up eight decades of dependency and go it alone wherever it can.