Putin's double down gives the West an opportunity

After humiliating reverses on the battlefield, Russia’s despot is trying to signal strength. Besides the nuclear threat, which Ukrainians dismissed as a bluff, he ordered a partial mobilisation, vowing to send soldiers to reinforce the Russian unit, and pledged support to puppet “republics” in Ukraine, which plan to hold referendums this weekend on whether to be annexed by Russia. These sham plebiscites, called at three days’ notice, will give Mr Putin a rhetorical excuse to treat Ukrainian attacks in Donbas as attacks on Russia itself, which could in theory invite nuclear retaliation. Mr Putin is doubling down on his disastrous war. …

Time is not on Mr Putin’s side. The reservists he is calling up do not need to be taught to shoot straight, but they need training to deal with new kit and local conditions. If deployed too soon, they will die in droves. They could be slotted into existing, depleted units to restore their strength. That would make it easier for Russia to defend its lines, though probably not to mount new offensives. It does not have enough weapons for a larger invasion force, not least because so many of its soldiers abandoned their guns and tanks when they fled recent Ukrainian advances. Realistically, it will be months before Mr Putin’s “partial mobilisation” makes a big difference in the field.

That gives Ukraine a window of opportunity. Its Western backers should step up the supply of arms, including longer-range missiles. The best nato weapons must not be used to attack Russia itself, but the parts of Ukraine that Russia is about to annex illegally should not be off-limits. The West should also train more Ukrainian soldiers. The country has plenty of highly motivated would-be defenders, but so far only Britain is offering basic training to large numbers. Other nato members should immediately pitch in, perhaps dividing the labour so that one ally focuses on air defence, another on artillery and so forth. The more of its land Ukraine can claw back before Russian reinforcements arrive, the stronger its position will be.