I keep hearing this and have yet seen any evidence that there anything we should have done in the early 90s.
The lack of interest at all levels with respect to Afghanistan in the early-mid 1990's came back to bite us in the ass. We had almost no one in the government who could speak Pashto or Dari. We had no insight into what was going on in the country. We had few contacts and those we had we generally ignored. All this left us with fewer options and less influence than we would have had when UBL became a threat, and it left us scrambling when 9/11 occurred.

I'm simply suggesting that we not repeat the mistake. We should certainly withdrawal military forces, but we need to be able to know what is going on in the country afterward and be positioned to influence events if necessary.