USAF (Ret.)

etired Col. "Randy" Larsen is no mild-mannered wonk. Asked to nominate people for this supplement, his first words were, "USA Today said I was America's leading homeland-security expert!" Larsen, 54, began his career flying Cobra helicopter gunships for the Army in Vietnam. He then transferred to the Air Force, where his assignments ranged from serving as chief of legislative affairs at Transportation Command to commander of the VIP aircraft unit at Andrews Air Force Base before becoming a professor at the National War College. In the late '90s, he co-authored several studies with fellow Air Force officer Robert Kadlec (now a top planner at the White House Office of Homeland Security) on the threat of biological terrorism. And after he retired from the military in 2000, Larsen took over the Institute for Homeland Security, a branch of the think tank ANSER. He also co-developed the seminal bioterror war game "Dark Winter"-a simulated smallpox outbreak in which retired Sen. Sam Nunn, D-Ga., role-played the president-held three months before September 11, 2001.

In May 2003, Larsen left ANSER to found Homeland Security Associates, a consulting firm of which he is CEO. "It was time to jump into the for-profit world," Larsen said. "I'm working with senior corporate executives to understand how homeland security, international terrorism, and transnational criminal organizations are going to change the business environment." What business really has to watch out for, he said is not the terrorists themselves, but over-reaction and over-regulation: "The greatest threat to our security is uncontrolled spending by Congress."

Born in New Castle, Ind., Larsen joined the Army at 19, earned his bachelor's at Southwest Texas State University, and went on to earn advanced degrees at the Naval Post Graduate School, the Air War College, and the Defense Intelligence College.