On Tuesday, they reset the Doomsday Clock to 90 seconds before midnight. How did they know that Germany would agree to give Leopard 2 tanks to Ukraine on Wednesday? Now we’re all doomed! Ninety seconds is barely time to tuck your head between your knees and kiss your posterior goodbye. The Doomsday Clock was thought up in 1947 by the Bulletin of the Atomic Scientists to dramatise the threat of nuclear war. They set it at seven minutes to midnight, and have been moving it back and forth every year since to tell us how close we were to a nuclear holocaust.

It dropped to 17 minutes to midnight after the end of the Cold War and the collapse of the Soviet Union in 1991. Now it’s just a minute and a half — the closest it has ever been — but may be it is just inflation, as with everything else. The Russians are certainly not panicking at the prospect of Leopard tanks with Ukrainian crews showing up to confront them in eastern Ukraine in a month or two (or three). A couple of weeks ago, Moscow hinted that this could be the step that ‘forced’ it to escalate to nuclear war, but that seems to have been the usual bluff.

Now that Western tanks actually are coming — American M1 Abrams, British Challengers, Leopard 2s from Germany and up to half a dozen other NATO members, probably Leclercs from France — the Russians are playing it cool. Kremlin’s spokesman, Dmitry Peskov, said that the new tanks “will burn like all the rest.” Some of them will burn, of course: there’s no such thing as an invulnerable tank. But the current rate of exchange, with old Soviet tanks on both sides, is two or three-to-one in favour of Ukraine, mainly because its crews are better trained and more committed. With better tanks than the Russians as well, the Ukrainian advantage will obviously widen.

The question is: will it widen enough for Ukraine to take back more Russian occupied territory, and if so how much? The new tanks are not wonder-weapons, and the fact that they will come in four different types is a logistical nightmare: different ammunition, different spare parts, and even different fuel in the US’s case. There will also not be very many of them, at least in this round of donations. A ‘company’ of tanks is fourteen or thereabouts, and Germany, the United Kingdom and Poland will be sending one company each. Smaller countries like Finland and the Czech Republic are unlikely to give more, and the United States of America is talking of about 30 M1s — two companies.

That means the total number of Western tanks being given to Ukraine is likely to be less than 100, whereas Ukrainians have always said that they need at least 300 to push the Russians back to their own borders. The long-planned Ukrainian winter offensive may have been cancelled because, first, the ground is still not frozen hard, and second, the new tanks will be in the hands of trained Ukrainian crews by the spring. The great Russian winter offensive is underway right now, but getting very little notice because it is making so little progress.

Let’s assume for a moment that the Ukrainians will wait till spring, that the new tanks make a difference, and that the Russians lose a lot more ground. Would that justify putting the Doomsday Clock ahead to ninety seconds to midnight? Winning in Ukraine may be an existential matter for the Russian dictator, Vladimir Putin, who has staked his reputation and perhaps even his life on making a success of the invasion, but it’s not a life-or-death issue for the ambitious men around him. They certainly don’t want to die for him, together with their entire families.

So the NATO assessment that a Russian resort to nuclear weapons in Ukraine is most unlikely, which underpins the NATO decision on the tanks, is almost certainly correct. How much of their country the Ukrainians can recapture remains to be seen, but they are at least free to try.