By Gideon Rachman
As US President Barack Obama and the leaders of the EU huddle together this week, they will strive to look united and resolved. The reality, as Vladimir Putin knows, is that they are divided and uncertain. The Russian president has moved with a speed and ruthlessness that has left western leaders floundering. Russia swallowed Crimea, in less than a week, with scarcely a shot fired. It has now massed troops on Ukraine’s eastern border – and all that the west has so far offered the Ukrainian military is a supply of US army ready-meals.