Am I wrong here that a collapsing Pakistan would essentially leave our boys stranded in Afghanistan without supplies (barring India taking Kashmir) or do we have friends to the north?
Are the troops in Afghanistan re-supplied by sea thru Karachi, then overland thru Pakistan to Afghanistan? I don't think they are.
Instead, I suspect the entire supply mission is via air -- over Pakistan.
Accordingly, the supply line should remain secure. Whoever is in charge of Pakistan loses no face when a C-17 crosses the country at 35,000 ft -- outtasight, outtamind so to speak. A truck convoy or a train is a different, more vulnerable matter.
But if some crazy lit off a guided missile or attempted an intercept of the C-17, the gates of hell would expectedly open. I don't think a Pakistani regime risks the outcome that creates a second, even more powerful enemy.