The charge against Donald Trump is about as serious as it is possible to imagine. He is accused, in effect, of having won office with the collusion of a hostile power. If he were guilty, it wouldn't just a scandal beyond the dreams of any thriller-writer; it would be the worst malfeasance in American history. There is an ugly word for people who act against their country's interest so as to advance that of an unfriendly regime.

Before we get too carried away, let's review the evidence. So far, there is no proof that Donald Trump collaborated with the Kremlin. Yes, there is evidence that the Kremlin interfered in the presidential election, hacking the emails of the Democratic Party with a view to prejudicing their campaign. But, at least to date, there is no indication that Donald Trump was working with Putin, let alone that he is some sort Manchurian-candidate Russian agent.

What are we to make of the news that his son met a Russian lawyer who claimed to have damaging information about Hillary Clinton? To Trump's supporters, it is no big deal: of course his team will have talked to representatives of big countries around the world, and there is no suggestion that anything illegal was discussed at the meeting. To his opponents, it is a further sign that the net is closing in. The New York Times, in particular, evidently sees l'affaire Russe as a new Watergate, in which each piece of information helps complete a picture that eventually shows Donald Trump doing something patently improper, and so forces his impeachment.

The NYT may be right though, to repeat, there has so far been no proof, and the presumption of innocence applies as much to presidents as to anyone else. What I find truly bizarre about the whole business, though, is the way Trump deals with Russia.

If you had had such accusations levelled against you, even if you knew them to be utterly baseless, how would you approach Vladimir Putin? Would you make it clear beyond doubt that you were behaving like previous administrations, ready to give a guarded welcome to Russian co-operation, but clear-eyed about the nature of the regime? Or would you suck up to Putin in a way that confirmed all your enemies' suspicions and sowed doubts among your friends?

Even before the inauguration, Trump was Tweeting his admiration for Putin. At the recent G20 summit, he seemed more at ease with the Russian strongman than with most of the democratic leaders.

Putin's objective, from the moment he took office, has been clear. He wants Russia to be feared and respected in the counsels of the world. He may preside over an economy no larger than Spain's, but he and many of his countrymen still think of Russia as a great global power. The more Putin can force Western nations to take him at his own estimate, the more popular he becomes at home.

Donald Trump is pretty much giving him what he wants. He seems prepared to overlook the reasons that previous administrations were not able to treat Russia as an ally: the annexation of bits of neighbouring countries, the murders of journalists, the repression of democratic opposition, the shooting down of an airliner filled with Western citizens. Of course, there are occasions when a certain wary co-operation in a limited theatre may be justified: it makes sense, for example, to avoid clashes when bombing Islamic State positions in Syria. But what happened at the Hamburg summit went well beyond that.

Trump Putin
US President Donald Trump and Russia's President Vladimir Putin shake hands during a meeting on the sidelines of the G20 Summit in Hamburg, Germany. Saul Loeb/AFP/Getty Images

"Putin & I discussed forming an impenetrable Cyber Security unit so that election hacking, & many other negative things, will be guarded and safe". Tweeted the President. The idea of inviting Russia, the chief aggressor when it comes to cyber-security, to pool its work with the United States is so utterly preposterous that it would be treated as a joke if it came from anyone other than the Commander-in-Chief.

As the excellent Nebraska Senator, Ben Sasse, promptly pointed out, also on Twitter: "This obviously should not happen--& obviously will not happen. Why the President of the United States would tweet it is inexplicably bizarre."

Perhaps responding to Sasse, the President returned to Twitter to issue what may be considered the most perfect, distillation of Trumpery: "The fact that President Putin and I discussed a Cyber Security unit doesn't mean I think it can happen. It can't-but a ceasefire can,& did!"

Got that? The fact that I said an impossible thing is irrelevant! And anyway, who says it's impossible?

It is almost as if Donald Trump is jutting his prominent chin at his critics and inviting them to take a swing. He may be wholly innocent of collusion with the Russians, but he seems to enjoy behaving like a man with something to hide. Maybe he doesn't grasp the gravity of what is being alleged; or perhaps he underestimates the hostility to Putinism on the Republican benches. But, unless he changes course, he will succeed only in uniting Congress against him.

Daniel Hannan has been Conservative MEP for the South East of England since 1999, and is Secretary-General of the Alliance of European Conservatives and Reformists. Follow : @danieljhannan