For a continent determined to present a united message of outrage and reprisals after the downing of Flight MH17 killed 211 of its citizens, the signals coming from the European Union this week have been contradictory. While its foreign ministers emerged from a meeting Tuesday vowing strong and unified action, a cross-channel spat over the sale of French warships to Russia exposed the depths of the economic conflicts which have prevented the EU from hitting Moscow with the toughest tools in its arsenal. Britain’s Prime Minister David Cameron said it was “unthinkable” that the UK would continue with the $1.62 billion warship deal, as France has done, given the Kremlin’s alleged backing of the Ukrainian rebels believed to have shot down the plane.