WASHINGTON — Colin Kahl, who has served for two years as the Pentagon’s policy chief under the Biden administration, will resign this summer.

Kahl, who the Senate confirmed as undersecretary of defense for policy in a party-line vote in April 2021, will return to his role as a professor at Stanford University, a Defense Department official familiar with Kahl’s plans told Defense News. The official, who spoke on the condition of anonymity because the individual was not authorized to talk publicly on the matter, said Kahl is still notifying his colleagues about the plan.

Kahl’s planned resignation was first reported by NBC News.

The official said that Stanford originally agreed to allow Kahl a two-year leave of absence from his professorship. But as that mid-April deadline approached, Kahl got Stanford’s permission to stay on a few months more.

The extension will allow Kahl to remain in his role supporting and advising Defense Secretary Lloyd Austin through the NATO Summit planned for July 11-12 in Vilnius, Lithuania, the official said.

The official said there is no specific date yet set for Kahl’s return to Stanford, but staying on for the Vilnius summit — which the official called an “important milestone event” for the department — will keep him in his current role at least through mid-July.

Kahl’s confirmation in 2021 was tumultuous, and Senate Republicans unanimously objected to making him the No. 3 civilian at the Pentagon. Some lawmakers criticized Kahl’s support for the Obama administration’s nuclear deal with Iran, and in his confirmation hearing he apologized for his “sometimes disrespectful” language in tweets harshly criticizing Republican lawmakers during the Trump administration.

The Senate Armed Services Committee ultimately deadlocked on his nomination, with Vice President Kamala Harris casting the tiebreaking vote in the Senate to advance his nomination. The Senate ultimately voted to confirm Kahl 49-45 when a few Republican senators were absent.

Before coming to the Pentagon two years ago, Kahl served as co-director of Stanford’s Center for International Security and Cooperation. He was also the first Steven C. Házy senior fellow at Stanford’s Freeman Spogli Institute for International Studies, as well as a political science professor.

Kahl served as deputy assistant to President Barack Obama and national security adviser to then-Vice President Joe Biden from 2014 to 2017.

Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.

More In Pentagon