Waller held a variety of staff and command positions which included: chief of staff, 24th Infantry Division (Mechanized), Fort Stewart, Georgia; Commanding General, 8th Infantry Division (Mechanized), V Corps, U.S. Army Europe and Seventh Army.

Waller was the deputy commander-in-chief for military operations with United States Central Command (Forward), during the Persian Gulf War.

Waller vehemently opposed, like most other military members, homosexuals serving openly in the United States Armed Forces.

During the 1993 U.S. Senate hearings on allowing homosexuals to serve openly in the United States military, Waller vigorously opposed it.

"[2] After retiring from the military, Waller moved to Denver, Colorado, and served as the president and chief executive officer of an environmental technology company, RKK Limited.