Because it would be suicide. Russia is fond of saber rattling and “oh-so-serious” threats about nukes, but Article 5 means they’re never attacking a NATO power. They don’t actually want to escalate either (I assume - it’d be catastrophically, titanically idiotic) but like a very, very small dog, have to yap loudly so nobody notices.

And over military aid? Nah. Best they can do is “punish” it by keeping sulking and whining hypocritically, same as they have been all along.