Other Afghans are getting angry. One U.S. commander in southern Afghanistan told me about his Afghan counterpart flaring up when he learned American support was being quickly scaled back. It's a dictum that "retrograde under contact" (withdrawal under pressure) is among the most difficult of military operations. At some point when troop levels have dropped, all a force can do is protect itself.

As U.S. forces withdraw after well over a decade of war, the insurgents have responded in various ways. IEDs continue to be the weapon of choice. Media-magnet complex attacks, such as the spectacular attacks on Kabul and Camp Bastion when Prince Harry was stationed there, broadcast the insurgency is still thriving.

In some formerly insecure provinces such as Khost, insurgent attacks have diminished. I asked Col. Sullivan about the contention that attacks dropped because casualty-cautious U.S. commanders ordered fewer combat patrols.

Sullivan challenged the idea that U.S. soldiers are not "out there," saying soldiers constantly travel the roads on retrograde convoys.

"We're not finding the mother lodes of caches (insurgent military supplies) when we go out," he says. "We're not getting a fight."

Then I asked about the assessment that Afghan insurgents are just husbanding their forces while the U.S. withdraws. "Husbanding of forces," Sullivan quickly agrees. "I might buy that."