He controls the Gas heating Europe.
He will not roll tanks. He will use money and political power.
Hardly a shot will be fired.
A bull market in Euro firewood this year?
That is the most likely scenario - the “Finlandization” of Europe.
Most Westerners would likely prefer domination by a foreign power over giving up their creature comforts or even their iPhones.
Heck here in the USA about half the population prefer free goodies over freedom from (government) slavery.