Did our leaders grasp the possible consequences of guaranteeing the security of a former Soviet republic with an eastern border only 100 miles from St Petersburg? At the time, Western governments probably assumed that signing up to fight for Estonia and its Baltic neighbours, Latvia and Lithuania, did not mean very much. After the momentous events of 2014, no one can entertain that comforting illusion any longer. In a Europe where Vladimir Putin has dismembered Ukraine, brazenly annexing 10,000 square miles of his neighbour’s territory, it should be abundantly clear that our pledge to safeguard the Baltic states is a deadly serious undertaking.