If anyone needed proof of how shallow and inadequate a political leader David Cameron is, then the debacle over Jean-Claude Juncker’s appointment should be a wake-up call. We are confronted with the spectacle of a Prime Minister who has traded the economic future of his country simply in order to appease a small, fanatical minority in his own party.

You think I jest? Well, if the Tories were to win a majority in next year’s general election (and, God knows, Miliband & Co are doing their best to ensure that they do), then Cameron is committed to holding an in-out referendum on the basis of whatever deal he has managed to negotiate with the EC. The Juncker fiasco has now guaranteed that he won’t get a favourable deal from Germany et al. So he will go to the country with an unimpressive case expecting to get a “yes, we stay in” result. Guess what will happen?

This is how my colleague Andrew Rawnsley puts it in this morning’s Observer:

He has predicated the success of that enterprise almost entirely on his relationship with the German chancellor. He has piled up all his chips on Frau Merkel. He has assumed that she would help him package up a renegotiation with enough “concessions” to Britain to allow him to recommend a yes vote in a referendum.

Crucially, he has also assumed that she can deliver everyone else to a deal as well. Some of us have been warning for some time that he has staked too much on Mrs Merkel. Yes, she is a highly skilled politician. Yes, she is the most powerful woman in Europe. Yes, she would like Britain to remain within the EU. But she is subject to her own domestic pressures – she isn’t where she is without being ruthlessly protective of her interests and she will not make huge sacrifices of her own political capital just to help Britain.

There are many lessons from this debacle for the Tory leader. One is – and this he really should have guessed already – that Mrs Merkel cares more about her own political skin than she does about David Cameron’s hide. If he can’t block a poorly regarded former prime minister of a very small country who has a notorious weakness for fermented fruit in liquid form, how is David Cameron going to succeed in his self-defined and much more challenging ambition of keeping Britain in the European Union after a renegotiation of the terms of membership?

Of course there are reasons for supposing that, even in those circs, the British will shrink from pulling out, once the appalling consequences of being outside the EU sink in. Some people have pointed out that the demographics of the British electorate point in an optimistic direction, in that younger people are significantly more pro-European than older people and the anti-Europe vote is strongest among the over-60s. The only problem with that is that the old tend to be more assiduous voters than the young.

Leaving the EU would be an economic catastrophe for Britain, as well as a cultural one. Every significant British industrialist understands that. The City understands it. Every university vice-chancellor knows it. Most serious politicians know it. Every significant policy adviser in Whitehall knows it. But they are all afraid to speak out because they fear a populist backlash, fuelled by tabloid xenophobia. (Some CBI bigwigs are already nursing the wounds inflicted on them by Scot CyberNats for daring to express negative opinions about the wisdom of Scottish independence.)

The thing about Cameron is that, deep down, he’s shallow. Now we know just how shallow. Still, I guess his good friend Rebekah Brooks will have sent him a LOL message after learning of his triumph at Ypres.