All Things Considered recently had an hour-long examination of Afghanistan and the U.S. role there and invited readers to send in questions for experts to answer.

Listeners did and some of their questions are answered by Thomas Hammes a senior military fellow at the National Defense University's Institute for National Strategic Studies; Max Boot, a senior fellow for national security studies at the Council on Foreign Relations, and Austin Long, an assistant professor of international and public affairs at Columbia University.

Richard Langer of Minneapolis, for instance, asks the experts if it's true that U.S. counterinsurgency doctrine would call for about 660,000 troops based on Afghanistan's 30 million population. The experts essentially say "Yes, but..." It's good reading.