Retired Marine Gen. John Allen Resigns as Top Think Tank’s President Amid Federal Probe

Gen. John Allen (ret. USMC), former Commander, International Security Assistance Forces, and Commander, U.S. Forces–Afghanistan, addresses delegates on the fourth and final day of the Democratic National Convention at Wells Fargo Center in Philadelphia on July 28, 2016. Saul Loeb/AFP via Getty Images

The head of the Brookings Institution resigned in the midst of a federal investigation into whether he lobbied the U.S. government on behalf of Qatar, according to a letter released on June 12.

Retired Marine Gen. John Allen, chief of the influential Washington-based think tank, wrote in his letter (pdf), “While I leave the institution with a heavy heart, I know it is best for all concerned at this moment.”