The situation on the ground is changing rapidly.

In short, it could be an orderly transition of power, or there could be chaos.

Order, chaos, making a political statement, those are the factors involved in the decision to enter the city, IMHO.

I thought it was a mistake to stay at the city limits.

The Taliban should have went in, establish control of a neighbour or two, to make it clear there is absolutely no way out of this mess.

If the Americans are upset at this, then so what?

After the Americans left Vietnam in the same chaotic way, we should not forgot how long it took for the Americans to reestablish diplomatic relations with the new Vietnam government.

Was it 2 years? 5 Years? 8 years? 10 years? 15 years? 20 years? 25 years?

It took 25 freaking years before the Americans opened diplomatic relations with the communist government of Vietnam.

The war is not over yet. Taliban should attempt to enter Kabul and take all strategic locations, or at least surround them and starve all resisters out.