Basically, don't piss off Poland, you'll need to defeat about 500,000 soldiers, though do you really need to march on to France if you win against Germany? Even if you did, that's about 1/3 the US military, and nowhere near as well armed, or well trained, or well psychologically prepared. If you're Russia, about 1 million soldiers should do the trick; and that's not hard when you don't have moral qualms and 21 million military age men to throw at the problem; and (edit) possibly an additional few million from North Korea for purchase.
As for nuclear weapons; Russia can probably bet that using a nuclear weapon from inside France, or inside the UK, as a first strike, would be too controversial to even do. The government would probably be sued by human rights lawyers from inside itself for even trying; convinced that it's better to take the loss while remaining on the moral high ground. What's even the point, when NATO predicts they have less than 5% of the defenses required for the inevitable retaliation? https://www.ft.com/content/5953405f-d91a-4598-8b6b-6345452ca...
> (edit to reply): Russia isn't winning against Ukraine.
"Don't piss off Poland?!" There won't be a large scale war against the Eastern EU started by Russia that does not involve Poland. The EU has stronger mutual defense clause than NATO article 5+6 (of course, it doesn't have anything close to the military might of the combined NATO countries). Once there is an all out war, Finland would mobilize its army, threatening Russia's northern flank. The Baltic would be closed. The black sea would be closed. All out war would be terrible, but the deterrence is still too strong in my opinion, as the price would be too high.
The problem / question is what would the EU (or NATO) do, if Russia starts a small scale hybrid war against Estonia or Latvia. Creating a small "local" insurgency, that takes over a majority Russian speaking town on the border. If the military alliances do not react united in such a case they are done.
I think the critical question is what would the allies do (especially the ones with nuclear weapons) if Russia actually used one. There's a lot of treaties, words spoken and on paper but nobody really knows how people would react to the idea of partaking in a nuclear war.
If they dropped a nuke on e.g. Lithuania would the French do the same knowing that retaliation would come that could wipe out most of their people and country off the map? Would any country do that for someone else?
> Even if you did, that's about 1/3 the US military, and nowhere near as well armed, or well trained, or well psychologically prepared.
Nowhere near as well armed as the US. But I would argue perfectly well trained. But I laugh at your assertion that the French military is not as psychologically prepared for war.
The population of Russia was widely disputed even before the war(With most estimates placing it at below 100M), and now it's basically a guessing game.
"that's not hard when you don't have moral qualms and 21 million military age men to throw at the problem"
But do you really have them?
Putin seems really hesitant to start a new round of mobilization and refills his army with volunteers. Some of which are voluntolds, but the regime seems to be afraid of the Moscow/St.Petersburg street, so to say.
His grip on the Russian nation, especially after 3 years of endless bloody slog with almost nothing gained, does not seem to reach into the "give millions of recruits weapons and they will use them exactly as told and there is no risk that they could rebel" territory.
Slovakia military: 25,000 people.
Polish military: 300,000 people.
Czechia military: 30,000 people.
German military: 183,000 people.
French military: 270,000 people.
Basically, don't piss off Poland, you'll need to defeat about 500,000 soldiers, though do you really need to march on to France if you win against Germany? Even if you did, that's about 1/3 the US military, and nowhere near as well armed, or well trained, or well psychologically prepared. If you're Russia, about 1 million soldiers should do the trick; and that's not hard when you don't have moral qualms and 21 million military age men to throw at the problem; and (edit) possibly an additional few million from North Korea for purchase.
As for nuclear weapons; Russia can probably bet that using a nuclear weapon from inside France, or inside the UK, as a first strike, would be too controversial to even do. The government would probably be sued by human rights lawyers from inside itself for even trying; convinced that it's better to take the loss while remaining on the moral high ground. What's even the point, when NATO predicts they have less than 5% of the defenses required for the inevitable retaliation? https://www.ft.com/content/5953405f-d91a-4598-8b6b-6345452ca...
> (edit to reply): Russia isn't winning against Ukraine.
Yet.