It is all the "other terrorist groups and hangers on" that flock to Afghanistan, if they are not already there that will be the problem to the outside world. The welfare, rights and wellbeing of the ordinary people of Afghanistan is a separate and important issue which must also be considered.

The "West" will have to decide how much of a terrorist training ground and safe haven they wish to tolerate Afghanistan becoming again before they are ready "to go back in".

Regardless of who actually owned the equipment left behind, I believe the biggest threat, regarding equipment, is where that equipment may eventually end up.

When the Soviets left Afghanistan and the Taliban took control they, the Taliban, could have equipped themselves with a fairly well equipped "army" with all the Sovieticon equipment that was left behind. That didn't appear to happen and I don't expect this time to be much different. The kit that doesn't end up in 3rd countries I fully expect to be "squandered and trashed".