President Barack Obama’s primary Pentagon adviser on Iraq, Colin Kahl, has returned to Georgetown as an associate professor in the School of Foreign Service after an almost three-year hiatus.

Kahl left his position as deputy assistant secretary of defense for the Middle East on Nov. 16, one day after the United States formally ended the War in Iraq.

“I’m turning back into an academic pumpkin after a three-year leave,” Kahl said to The Cable, a blog published by Foreign Policy magazine. “I had a timeline for leaving just like the [United States] had a timeline for leaving. It wasn’t a coincidence.”

Kahl was awarded the Secretary of Defense Medal for Outstanding Public Service by Secretary of Defense Robert Gates in June 2011 for his work in the U.S. government.

Kahl left the university in February 2009 on a two-year leave to advise the Obama administration during the country’s withdrawal from Iraq. Last year, Gates asked Georgetown to allow Kahl to remain at the Pentagon until the end of this year, a request that was granted.

Next semester, Kahl will teach a security studies course entitled “Iran and the Bomb,” which he has taught previously. His research and courses focus on international security, foreign policy in the Middle East and terrorism.

Kahl will also be resuming his work as a senior fellow on the Middle East at the Center for a New American Security, a D.C.-based think tank, specializing in U.S. national security.