From July 1956 to December 1957, Kelley served as the Special Assistant to the Director of Personnel at Headquarters Marine Corps, Washington, D.C.

In February 1980, Kelley was promoted to lieutenant general and named as the first Commander of the Rapid Deployment Joint Task Force.

On 21 March 1966, during Operation TEXAS, Lieutenant Colonel Kelley led his Battalion in a helicopter assault on a Viet Cong fortified area in Quang Ngai Province.

Debarking from his helicopter into accurate, intense enemy fire, he realized that the landing zone must be enlarged in order to bring in the balance of the Battalion safely.

With great professional competence and composure, he maneuvered his Companies into position to attack the enemy, employing all available supporting arms.

In the attack phase, with complete disregard for his own safety, Lieutenant Colonel Kelley placed himself in a strategic, exposed position from which he could best control the assault companies and supporting arms.

At the conclusion of the vicious three and a half hour battle, Lieutenant Colonel Kelley's Battalion had accounted for 167 Viet Cong killed, many small arms and crew served weapons captured, and tons of supplies destroyed.

By his daring leadership, relentless fighting spirit and unswerving dedication to duty throughout, Lieutenant Colonel Kelley upheld the highest traditions of the United States Naval Service.In 1989, Kelley joined the Washington, D.C. public policy firm Cassidy & Associates; he served as the Vice Chairman Emeritus.

[6][7] In December 2006, Kelley chaired a panel of military and business leaders looking to improve the United States's energy security.

They recommended tougher emission standards and greater access to offshore United States gas and oil reserves.

[8] On July 26, 2007, the Washington Post published an op-ed by Kelley and Robert F. Turner, in which they warned that the July 20, 2007 executive order issued by President George W. Bush, purporting to define torture and allowable interrogation methods, appeared to violate Common Article 3 of the Geneva Conventions and thus expose the President and other persons to potential liability for war crimes.