America's all-volunteer armed forces have led to a growing and dangerous gap between the military and civilian spheres, making it too easy for politicians to order risky deployments with casualties borne by a small, mostly low-income group that does not represent society as a whole, a Stanford historian said Monday.

Pulitzer Prize-winning history professor David Kennedy spoke to a standing-room-only crowd of about 150 people in a public Veterans Day lecture organized by the Stanford Historical Society.

It's been 40 years since the U.S. eliminated the draft in 1973 in favor of an all-volunteer military force, a decision Kennedy argued has adversely affected society and boosted the risk of military adventurism....