>Russia remains bogged down in Ukraine. But Putin does not need another invasion on the scale of Ukraine to challenge NATO. He can move up an escalation ladder: sabotage, cyberattacks, assassination plots, drone or missile attacks — and then a limited military operation designed to test whether NATO still means what it says.

So Russia is too weak to conquer Ukraine but wants to risk other countries joining hot war? What for? Get bogged down even more?

You assume rationality when history has shown wars are often started with irrational or no apparent reason.

It's disturbing how much of leadership is based on arbitrary decisions. Military included.