A senior investigator has resigned from the Republican House Foreign Affairs Committee probe into the Biden administration’s deadly and chaotic withdrawal from Afghanistan in August 2021, accusing the panel of holding back its full power in examining the failures of the U.S. pullout.

Jerry Dunleavy, a former journalist and author of a book detailing first-person accounts of the withdrawal, posted his resignation letter Monday to social platform X. He described himself as a whistleblower, criticizing the committee as suffering from “investigative paralysis.”

Efforts to pursue investigative leads were “repeatedly stymied by our chief investigator and by senior staff, and unfortunately, sometimes by indecision from you, Mr. Chairman,” Dunleavy wrote in the letter, referring to House Foreign Affairs Committee Chair Michael McCaul (R-Texas).

In a phone call with The Hill, Dunleavy said he was motivated to speak out publicly ahead of the November election to raise an urgency to go after interviews with key administration officials and dig deeper into the responsibility of the military generals and commanders while Republicans are still in the majority in the House.

“There is definitely a significant bias from the chairman, downward, toward not really looking to hold the military commanders and generals accountable for what happened,” Dunleavy said.

He described committee members treating retired Gens. Mark Milley and Kenneth McKenzie with “kid gloves” during a March hearing. Milley served as chair of the Joint Chiefs of Staff during both the Trump and Biden administrations, and McKenzie is the former commander of United States Central Command.

Dunleavy further said that the committee has taken “zero steps” to look at Vice President Harris’s role in the U.S. withdrawal from Afghanistan, saying “I have received pushback from my superiors related to taking action on this.”

“I have argued repeatedly that Vice President Kamala Harris should be held accountable for her role in the debacle in Afghanistan, especially now that she is the Democratic nominee for President of the United States and could soon be making national security decisions and directing foreign policy for our entire nation,” Dunleavy wrote in his letter.

Emily Cassil, a spokesperson for committee Republicans, responded to Dunleavy’s resignation by saying McCaul “pours his heart and soul into getting answers for our Gold Star families and Afghanistan veterans” and pointed to the committee’s expected publication in September of its final report looking at the decisionmaking surrounding the U.S. pullout.

Separately, a Republican committee aide pushed back on Dunleavey’s assertion that the vice president was off limits, adding that her role in the withdrawal would be addressed in the September report.

McCaul has made investigating President Biden’s 2021 withdrawal from Afghanistan a centerpiece of his agenda heading the committee, promising to discover how the two-decade war culminated in a deadly and chaotic end in which 13 U.S. service members were killed in a terrorist attack, along with roughly 170 Afghan civilians.

But Democrats have criticized McCaul as carrying out a partisan investigation that fails to look at former President Trump’s role in setting up the conditions for the U.S. exit from Afghanistan, as well as decisions by previous administrations from Presidents Bush and Obama.

McCaul’s staff published an interim report in August 2022 that detailed a lack of planning on the part of the administration and analyzed a series of missteps and errors that complicated the withdrawal.

The final Republican committee report is expected to be based on more than 20 transcribed interviews with administration officials involved in the withdrawal and conclusions drawn from at least five public hearings carried out over the course of the year.

The U.S. military and diplomatic withdrawal from Afghanistan is largely viewed as one of the darkest moments in Biden’s term in office. Over a fraught two weeks in August 2021, the U.S. watched the Taliban advance a lightning offensive to take over the country, sweeping through Kabul as the internationally recognized Afghan government and military crumbled.

The administration evacuated an estimated 125,000 people over those two weeks, but tens of thousands of vulnerable Afghans who worked alongside U.S. forces were initially left behind, and pathways to immigration to the U.S. got caught up in a bureaucratic backlog.

The withdrawal was marked by hectic scenes of civilians mobbing Kabul’s Hamid Karzai International Airport and departing planes. A deadly terrorist bombing by the group ISIS-K left more than a dozen U.S. forces dead.

“I don’t want there to be more unnecessary Gold Star families in the future,” Dunleavy told The Hill.

“That’s what I worry about, if we don’t pursue real accountability and pursue real answers here is that there aren’t going to be lessons learned. There’s not going to be accountability, no one’s going to feel like there needs to be a big mindset change. No one’s gonna really absorb the fact that this was a big loss. We lost a two decade war, and we better get serious if we don’t want to lose the next one.”