Russian President Vladimir Putin is bringing his war in Ukraine home. It’s a desperate move that could imperil Putin’s control of Russia and have momentous implications for Ukraine’s US and European allies.

Putin announced a “partial mobilization” policy on Sept. 21, allowing the government to call some 300,000 Russians with military experience back into service. Since Russia invaded Ukraine on Feb. 24, Putin has avoided any kind of mobilization that would force ordinary Russians into uniform, relying on a peacetime military staffed with paid enlistees, career professionals, and an assortment of others.

But Ukraine’s successes on the battlefield, including the recent lightning offense in northeast Ukraine, have left Russia’s army badly depleted and desperate for new troops.

At the same time, Putin plans to impose a series of forced “referendums” in Ukrainian territory Russia controls, with outcomes meant to show that vast majorities of Ukrainians want Russia to annex their land and make it part of Russia.

Most people in those occupied areas want no such thing. However, a rigged vote to join Russia will give Putin a pretext for claiming those territories belong to Russia so that any foreign military efforts there is an attack on Russia itself.

That fuels Putin’s bogus claim that his war in Ukraine is necessary because of western aggression against Russia.

It also sets conditions for Russia’s possible use of nuclear weapons, which Putin has consistently hinted at, including in his Sept. 21 address. If Putin were to take this unprecedented step, he’d want to claim he had no choice but to use nukes, because Russia’s survival is at stake.

That’s a fiction none of Ukraine’s allies will accept, but Putin may think it helps justify the use of nukes or other extreme measures.

All of this reveals that Putin knows he’s losing in Ukraine and is willing to take some of the biggest risks of his political career to change course. That makes the war more dangerous and the possible consequences more profound.