That was a political failure of gigantic proportions – to lack the guile and intuition to realise that patience with Britain's idiosyncratic approach to Europe had long been wearing thin in Brussels, Paris and Berlin – particularly as they grappled with more pressing economic issues than Cameron's local difficulties with the Eurosceptics.

But this was also a personal failure. Cameron has allowed his relationships with Sarkozy and Merkel to deteriorate to such an extent that he could not read the signals hinting that they would give him nothing. He seems to have failed to develop the personal relationships with Europe's leaders that might have encouraged a willingness to accommodate Britain's wishes. There are alarming signs that he lacks the emotional intelligence that a first-order statesman needs if they are to take a seat at the table of political history – forming alliances, building support, accruing political capital, nudging, cajoling. And ultimately winning. If, on the other hand, the prime minister is looking to isolate, alienate and lose the trust of political colleagues and partners, particularly at such a perilous time, then he's showing all the right qualities.