At first, when I heard of Ukrainian strikes into Russian territory, the downsides did not immediately occur to me.  Like most Americans, I sympathize with the Ukrainians, who are being devastated by the war Russia has inflicted on them.  And with tremendous damage being done to Ukraine, it seemed only fair to hit back at Russia.

But thanks to a Twitter thread unrolled here, I am convinced by the author, Clint Ehrlich, that the strikes into Russia are, in his words, "a great tactic — but a horrible strategy."  Mark Wauck excerpted some of the key statements from the thread, which I copy below:

Putin can respond by declaring war on Ukraine, making millions of conscripts available.

The conflict would grow to an apocalyptic scale matching WW2.

There have already been a series of mysterious fires and explosions inside Russian territory.

Many of these involve facilities needed for the war effort.

For example, Russia alleges that Ukrainian helicopters blew up an oil-storage depot in Belgorod, Russia.

And Ukrainian drones recently penetrated 140 miles into Russian territory.

At the same time, blasts at nearby Russian military facilities allegedly killed multiple soldiers.

It looks like it may be part of a targeted campaign to strike inside Russia.

This campaign is receiving the full support of the West.

Britain's Defense Minister said yesterday it was "completely legitimate" for Ukraine to use UK weapons to strike inside Russia.

He said "Ukraine needs to strike into its opponent's depth" to win the war.

No one can disagree that, when a country is invaded, it has a right to launch counter-attacks.

But that does not mean it is *wise* to do so.

I fear that Western support for Ukrainian attacks inside Russia will backfire – and may risk the complete destruction of Ukraine. 

To date, Vladimir Putin has insisted that what is happening in Ukraine is a "special military operation."

Because Russia has not declared war, it has not begun a full-scale military mobilization.

In effect, it has been fighting with one hand tied behind its back.

If combat were restricted to Ukraine's territory, then it would have been politically difficult for Putin to justify placing Russia on a full wartime footing.

But cross-border attacks change the political calculus.

They make it seem that the Russian homeland is under threat.

It may benefit Western readers to imagine a similar scenario playing out inside America.

If a U.S. President were losing a foreign war, it would be difficult to justify the draft.

But if the enemy started launching attacks inside America, that option could be on the table.

Full Russian military mobilization would vastly change the strategic picture inside Ukraine.

On paper, Russia has a much larger military, but it has been limited to contracted soldiers.

As a result, it has deployed fewer than 200k troops in its non-war "operation."

That represents approximately 50% of the 400,000 contract soldiers in Russia's active-duty military.

The remaining 600,000 active-duty Russian soldiers are conscripts, whom Russia technically cannot use outside of wartime territorial defense. 

Because Ukraine initiated a full-scale mobilization of conscripts at the beginning of the conflict, it has enjoyed numerical parity with Russia.

Many Western analysts believe that its forces actually outnumber Russians on the ground.

However, if Russia begins a full national mobilization, its troops will *vastly* outnumber Ukraine's forces.

It not only will gain access to all ~1 million active-duty soldiers, it will be able to call up ~2 million reserves.

To be clear, these soldiers would not all be deployed into the Ukrainian theater.

Reserves would be largely unfit for combat, and Russia must keep sufficient forces stationed to defend its own vast territory from e.g. China.

But the manpower boost would be enormous.

Russia may also be willing to deploy a surprising percentage of its conventional military to Ukraine.

Even worse than Putin mobilizing his full military capability is the possibility of using nukes.  I am not fully persuaded by Ehrlich's logic here, but given the gravity of a nuclear confrontation, it is worthwhile hearing what he has to say.

This is an under-appreciated aspect of Putin's recent emphasis on Russia's readiness to use nuclear weapons if threatened.

The immediate target of Putin's nuclear rhetoric is the West.

But the subtext is that *any* potential adversary should be ready to be struck with Russian nukes.

That includes China if it were to make territorial incursions into Russia's Far East.

From a game-theoretic perspective, President Putin can make his nuclear threats *more* credible by over-deploying Russian forces into Ukraine.

If Russia sacrifices its ability to defend its territory conventionally, it effectively *pre-commits* to using nukes. 

Back to Russia fully mobilizing:

What we are discussing is, of course, military mobilization on a scale that has not been since World War 2.

But the groundwork for such a mobilization is already being laid by the domestic political rhetoric within Russia. 

Russia's Foreign Minister, Sergey Lavrov, has argued that the country is now fighting a proxy war against NATO, where Ukraine is simply the battlefield.

He says the risk of a "third world war" is now "serious, real. It should not be understated."

At the same time, Russia's government has sought to invoke the memory of WW2 to justify the current conflict.

This goes beyond merely calling the Ukrainian regime as Nazis.

The symbol "Z" has been rebranded as standing for 77 years since the Great Patriotic War.

The trillion-dollar question is whether the Russian people will go along with their government's claim that a sequel to World War 2 needs to be fought.

So far, it isn't clear that they're ready.

But if Ukraine continues attacking inside Russia, that could change quickly.

It doesn't matter if Ukraine e.g. limits its attacks to military infrastructure where Russian civilians are unlikely to die.

Once the Ukrainian campaign is underway, Russia will easily be able to blame Zelensky's government for *any* explosions or fires on its territory.

Too many Western leaders and analysts are patting themselves on the back, imagining that Russia's original war aims can never be accomplished.

They are imagining that Kiev is safe and the only question is whether Ukraine will prevail in the Donbas.

In reality, Putin still remains determined to delivery victory.

And supporting Ukrainian attacks inside Russia gives him the blueprint he needs to reset the war.

Once he has a viable political path to call up millions of reserves, why should we assume he won't take it? 

A fully mobilized Russia would be capable of not just taking the Donbas, but of invading Kiev and seizing all of Ukraine.

Putin would position himself as a war-time President equal in status to Stalin – the man who took on NATO in Ukraine and won.

Yes, this will entail massive Russian casualties.

Yes, it will result in civilian deaths on a horrifying scale.

But none of that's a reason to believe it won't happen.

It's a reason we should try to *stop* the nightmare scenario, before it becomes real. Before it's too late.

A negotiated peace still likely is within reach — and, given the scale of death and destruction being inflicted on the Ukrainians, ought to be a top priority of our diplomacy.

Damage in  Kyiv (YouTube screen grab).

But instead, our leadership seems to want to bleed Russia, with no regard for the human suffering that this strategy necessitates.