A former Marine who fought in Iraq, joined the State Department after leaving the military and was a diplomat in a Taliban stronghold in Afghanistan has become the first U.S. official to resign in protest of the Afghan war, the Washington Post reported early Tuesday.

Matthew Hoh, who describes himself as “not some peacenik, pot-smoking hippie who wants everyone to be in love,” said he believes the war is simply fueling the insurgency.

“I have lost understanding of and confidence in the strategic purposes of the United States’ presence in Afghanistan,” Hoh wrote in his resignation letter, dated Sept. 10 but published early Tuesday. “I have doubts and reservations about our current strategy and planned future strategy, but my resignation is based not upon how we are pursuing this war, but why and to what end.”

The move sent ripples all the way to the White House, the paper said, where officials immediately appealed for him to stay out of fear he could become a leading critic.

U.S. Ambassador Karl Eikenberry brought him to Kabul and offered him a job on his senior embassy staff, but Hoh declined. He then flew home and met with Richard Holbrooke, the administration’s special representative for Afghanistan and Pakistan.