Finally, Germany has decided to get ahead of Russian aggression – by sending 5,000 helmets to Ukraine. Geddit?

The mayor of Kyiv thought it sounded like “an absolute joke” too, demanding to know: “What will they give us next? Pillows?” But with great solemnity, German defence minister Christine Lambrecht called the donation of helmets “a very clear signal”. I suppose it is, although not quite in the way that she intends.

This is the best Nato can do, however. In a debate in Parliament this week, Boris Johnson was asked repeatedly whether we ought not to keep our 1994 promise to guarantee Ukrainian territorial integrity, even though Kyiv isn’t a Nato member, by sending troops to do some actual fighting. His answer was to shrug sympathetically and admit, in a roundabout way, that no one was really up for that.

It’s not even apparent that the West is prepared to impose the harshest economic sanctions it could muster, despite a lot of rhetoric along these lines. Olaf Scholz, Germany’s chancellor, won’t say a word publicly about cutting Russia’s banks off from Swift, the international payments system, let alone talk about cancelling Nord Stream 2, Moscow’s huge energy weapon pointed at the heart of Europe.

Meanwhile, Emmanuel Macron continues his desperate campaign to stay relevant by promising “never” to give up on dialogue with Russia, holding phone calls with Vladimir Putin and proposing various formats for new talks about old issues. To be fair, at least France has deployed troops to Romania, mirroring the UK’s commitment to Estonia.

The UK has gone hard on rhetoric and, like the US, has sent some serious weapons to Kyiv, but so far has been peculiarly vague in its threat of sanctions. Britain has sanctioned many fewer Russian officials than the US and has still not made full use of its power over the assets of Mr Putin and his inner circle, who keep hordes of their wealth in London. There is no convincing answer from the Government as to why that is.

In truth, the West is suffering from a bad case of boiled frog syndrome. The old adage goes that if you put a frog into boiling water, it will jump out, but if you start with the water cold, you can boil it by heating up the pan slowly (why anyone but a Frenchman would want to do this is unclear).

For years now, the Western alliance has agreed to be boiled. The unknown question is what, if anything, will finally prompt us to jump out.

The whole point of Nato, after all, is not to go to war but to avoid it. Its watchword is deterrence. But deterrence only works if you are able to issue credible threats and no one believes us anymore because we don’t even believe ourselves.

Would we really go to war to protect the sovereignty of Estonia, a Nato member, for example? We don’t want to know – but Mr Putin does.

All the signals we send suggest the answer is “no”. There has been no serious effort to wean Europe off Russian gas. And ever since the Iraq War, Western publics have been reluctant to back fighting of any kind, while their leaders are unwilling to challenge this attitude.

The logical result was the catastrophically mismanaged withdrawal from Afghanistan, a final unwinding of the post-9/11 over-expansion in Western ambition and a global humiliation for the US. One of the stated aims of the rout of Kabul, according to Joe Biden, was to give Washington new space to refine its strategic objectives and pivot from the Middle East and Russia to confront China. Well, that has worked out wonderfully well, hasn’t it?

China, for its part, is a skilled boiler of the Western frog. Lithuania is a prime example. The small Baltic state has been given a classic Beijing punishment beating recently, complete with trade embargoes and threats, ever since allowing Taiwan to open a de facto embassy in its capital. The EU tried to support its member state, but was quickly sabotaged by Germany, which fears a spat with China might hurt its own exports. As ever, you can rely on Germany to lecture us all about our values while doing everything it can to undermine them.

Aside from Russian gas, German duplicity and the Iraq effect, there is of course the ultimate logic of a nuclear-armed world. If Nato troops ever meet Russian troops in battle, there is the unavoidable risk of escalation to a nuclear strike in one way or another. It would no doubt be difficult to find anyone outside Estonia who thinks that its territorial integrity is worth the risk of nuclear war. This can only make the deal Ukraine took – never to develop nukes in return for a guarantee of territorial integrity – all the more bitter.

At any rate, how far can we really allow Mr Putin to press this logic? It is an argument that justifies almost any amount of surrender and submission.

If we are constantly cowering before the fear of Armageddon, we only invite our enemies to push the boundaries further and further until they reach a genuine red line (some piece of Finland? Romania?) and a disastrous confrontation becomes inevitable.

The only comfort Nato supporters can take from the situation, and it is very thin comfort, is that Mr Putin now runs the risk of strengthening the very alliance he fears. Finland and Sweden have revived their debates about joining Nato. Defence spending in many countries will surely begin to rise.

Even Ireland, officially “neutral” on all military matters, has chosen to notice that Russia may have parked a missile-armed submarine in an underwater valley in its waters. Its response? The Russian ambassador has been warned, in no uncertain terms, that this activity constitutes a severe and unprovoked threat to any sperm whales who happen to be in the area. I wish, again, that I was joking.

At some point, a reckoning will come for Nato. Perhaps we had better hope that it comes sooner, rather than later, before the frog has been totally cooked.

Otherwise, we may have to start regarding Nato’s confusing motto as the defining feature of the alliance. Animus in consulendo liber is a quote attributed to Cato, copied from the back of a magistrate’s chair in Italy and emblazoned on the wall of Nato’s conference room 16.

So what does it mean? According to Nato’s own website: “A satisfactory translation of the phrase has not been found.”

This rather brings to mind Sun Tzu’s adage: “If you know neither the enemy nor yourself, you will succumb in every battle.” In the light of which, can I suggest that we at least arrive at some degree of self-knowledge and refine Nato’s motto thus: “I joined Nato and all I got was this lousy helmet.”