According to Sir Roly Walker, the UK's Chief of the General Staff, while at this rate it will take Russia five years to secure all of the Donbas, the West needs to be ready for war with some unholy alliance of Russia, China, Iran and North Korea within three. Can one really imagine Vladimir Putin, still locked in conflict with Ukraine, also taking on Nato? And with what?

At times, there almost seems to be some kind of bidding war between officials and commentators, as they predict ever-tighter timetables of the apocalypse. The German think tank the DGAP released a report suggesting that Nato has just "five to nine years" to get ready to deter or repel a Russian onslaught. Jacek Siewiera, head of Poland's National Security Bureau, called this “optimistic” and suggested it was just three years — but given that he said this last December, that's just two and a half years away now.

Yet at the same time, we hear daily accounts of the pressures on the Russian war economy, the shrinking of stocks of dated tanks being thrown into service, the desperate search for more soldiers to throw into the meatgrinder. Given that a military machine that took two decades to build has largely been destroyed, replaced by one cobbled together from spare parts, dated stock, field expedients and a relative handful of new systems, how can the West face such a formidable challenge so soon — and why?

The classic formulation is that threat = intent + capability. Intent is, of course, notoriously and monstrously difficult to assess given that people have a regrettable tendency to lie to others and to themselves, to change their minds and to have them changed for them. Some say that Putin will be determined to avenge himself on a West that supported Ukraine, others that he has wider territorial ambitions. Personally, I find this hard to credit — it is clear from his pontifications in print and on TV that Ukraine, and eastern Ukraine in particular, are special to him. He believes it to be part of Moscow's rightful historical patrimony. Although some of the usual chorus of toxic pundits extend this to Finland, Poland and other territories once under Soviet or tsarist rule, this has never been Putin's mission. Indeed, that Nato membership is regarded by him as something of a shield is evident in his attempts for so long to warn Sweden and Finland off membership, and his unwillingness to countenance Ukrainian membership.

Nonetheless, as it is impossible to be sure what he intends now, let alone years into the future, it will perhaps be more fruitful to consider capabilities.

The damage done to the Russian war machine is even greater than would be suggested by the tally of systems destroyed and lives lost — perhaps half a million dead and wounded to date. Putin deployed many of his best troops in the early and most misguided stage of the war: the Spetsnaz commandos, the Airborne, the Naval Infantry. They suffered savage losses to their most capable and experienced men, and even if the units still exist in the order of battle, they are skeletal or packed with under-trained replacements. Even the training cadres which would impart the necessary skills to conscripts and volunteers alike were thrown into battle, and suffered accordingly. The issue is not just one of making up the numbers, it is of a profound de-skilling.

Likewise, industrial production is currently able to keep up with the costs of the war thanks to a dwindling stock of old frames ready to be refurbished. In the last year, Russia fielded some extra 2,000 tanks, which made up for losses in purely numerical terms. However, only around 200 were brand new, the rest being taken out of mothballs. Some were 1960s tanks, and although many received a degree of modernisation, including extra armour and more modern sights, they are not the equal of their contemporary counterparts. More to the point, these stocks of Cold War kit are not inexhaustible.

The Russian defence industrial sector is already operating flat out — there is no more spare capacity, especially not in producing complex systems. At 200 tanks a year, for example, then assuming the war ended tomorrow, it would still take more than a decade to rebuild stocks. That, of course, depends on the Kremlin being able and willing to continue to spend at the current rate.

It is easy to say that an autocrat like Putin doesn’t have to worry about the constraints of politics or economics, but of course he does. The economy is already overheating, and there are signs of restiveness beneath the enforced veneer of patriotic enthusiasm. If anything, the stakes are higher for an autocrat, who cannot count on the loyalty of his elites or the prospect of a comfortable retirement if he pushes his people too far.

This is also a question of industrial longevity. At the current breakneck pace, machinery will wear out and break down all the sooner. Can the factories keep running at this pace, even if the workers and money are still there? Of course, the Russian military is learning invaluable lessons in the war, which does make it more capable and dangerous. Yet reconstituting its forces would likely take 7-8 years at the absolute minimum, and that after this war ends. A Russian victory looks unlikely, but so too at present does a defeat, and so this war may well not be over soon.

Besides, Nato is spending more than ever, and even those countries which in the past happily freeloaded on their allies are increasing their defence budgets. The lessons of the Ukrainian battlefield are also being incorporated into Western designs and doctrine. In five years, let alone ten, Nato will be even more formidable — and it already has more troops and better capabilities than the Russians when they were at their peak. Of course, all of this costs money, and requires sustained effort, and maybe that helps explain some of the more strident claims of Putin's malign intent and imminent threat. Nothing helps concentrate the public mind better than a bugbear in the east.

Mark Galeotti is director of consultancy Mayak Intelligence and honorary professor at UCL School of Slavonic & East European Studies.