They are all on a timeline. They have to do it while Biden is president.
After watching him manage the Afghan retreat, I'd say they're on to something. It's too bad for the people who will suffer from this incompetence.
Yes, a window of opportunity has been opened for our adversaries and they won’t miss taking advantage of it.
Weakness invites aggression. Always has, always will.
“They are all on a timeline. They have to do it while Biden is president.”
They may be considering which Party is in control of Congress as well.
Seasonal factors play in the planning as well.
When the ground is frozen, tanks can maneuver freely over the fields. When Spring rains come, they may often be confined to roads, where they are more vulnerable to mines and anti-tank missile ambushes.
They would likely plan to secure some Strategic objective(s) before mud season, which would drive the schedule to start the operation. I don’t know what the scale of their ambition is (if they want to take the whole Country, or just some parts, or just force a regime change to a friendly Administration).
Whatever their thinking, Biden in the White House surely tempts them aim higher, and to take the gamble.
Weakness invites aggression.