From what I understand, there are semi-rational reasons for which Putin might have wanted to attack Ukraine in 2022 and not wait, for instance, 10 more years to

From what I understand, there are semi-rational reasons for which Putin might have wanted to attack Ukraine in 2022 and not wait, for instance, 10 more years to ensure that Europe could not wean itself of Russian resources. - Despite Russian propaganda to the contrary, the Russian army is still going to pieces. Yes, there is a stronger professional core now than there used to be during the 90s, but that core is shrinking because the military has difficulties both funding itself, attracting new recruits, and with endemic corruption. Some of the reasons for which it has difficulties attracting new recruits are that the Russian population is growing old very quickly and emigration is attractive to whoever can afford to leave. - Historically, Russian doctrine is to assume that an invasion is coming from the West. Always. History shows of a few places where such an invasion can be stopped fairly easily, if Russia controls them. As it turns out, two of the lynchpins are respsectively in Ukraine in Poland. Since the army is getting weaker and there is a chance that Ukraine could join NATO, if Russia wants to grab control of the lynchpins, it has to attack as early as possible, before the imbalance grows worse. - The fact that PRC is eyeing towards Taiwan means that the US cannot commit too many forces in Ukraine. There is a risk that PRC might end up subjugating Taiwan either semi-peacefully or at least so fast that the US doesn't get a chance to react, in which case the window of opportunity would close.