Poland’s attitude and actions aggravated Russia for centuries. In the years 1611–12, during the turmoil in Russia, the Polish-Lithuanian army controlled Moscow. Since Napoleon’s conquest of Moscow in 1812 was his great defeat, for the Russians, this Polish incident is the only case in which a foreign power ruled in modern Russia, i.e. after 1480. They remember that. In 2005 Putin established a national holiday on November 4, the day Poles were kicked out of Moscow in 1612.

I agree with you that using nuclear weapons would be irrational. Roughly as much as irrational was the invasion of Ukraine. Hence, I would not bet my money that Russia will act rationally under Putin’s leadership.