Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He is the author of "Manhunt: The Ten-Year Search for bin Laden -- From 9/11 to Abbottabad."

(CNN) Lt. Col. Jason Amerine, a Special Forces war hero who played an instrumental role in the overthrow of the Taliban in the months after 9/11, is under investigation over a purported unauthorized disclosure relating to a U.S. hostage held overseas that was made to U.S. Rep. Duncan Hunter's office.

Hunter, a California Republican, has been a vocal advocate in Congress for pushing efforts to help free American hostages held by al Qaeda and the Taliban

A plan was developed in the Pentagon by Amerine, most recently a planner on the U.S. Army staff, to secure the release of those American hostages, according to a staff member on Hunter's committee.

The plan was to release Haji Bashir Noorzai, a prominent member of the Taliban who is in prison in the States on drug trafficking charges, in exchange for U.S. Army Sgt. Bowe Berghdal , who was held by the Taliban until last year as well as other Taliban hostages. They were: Caitlin Coleman, a U.S. citizen, and her husband, Canadian citizen Joshua Boyle, and Warren Weinstein , an American aid worker held by al Qaeda who was inadvertently killed in a CIA drone strike in January

It's not clear how far, if anywhere, this plan of action went.

The Washington Post reported Tuesday that the Army Criminal Investigation Command is probing what Amerine may have disclosed to members of Congress months ago. Chris Grey, a spokesman for the Criminal Investigation Command told the Post that, "As a matter of policy, we do not confirm the names of individuals who may or may not be under investigation to protect the integrity of a possible ongoing investigation, as well as the privacy rights of all involved." He also said, "We reject any notion that Army CID initiates felony criminal investigations for any other purpose than to fairly and impartially investigate credible criminal allegations that have been discovered or brought forward."

In a Facebook post this month, Amerine made his first public comments about the investigation, writing: "I have been under criminal investigation for the last four months for whistleblowing to Congress over our completely dysfunctional system for recovering hostages. The FBI formally complained to the Army about me reporting to Congress about their failed efforts to recover Warren Weinstein, Caitlin Coleman and the child she bore in captivity...If I learned nothing in my 22 years of service I learned that we never leave people behind."

What makes the investigation of Amerine so strange is that he is a bona fide war hero. According to research that I conducted for "The Longest War," a history of the war on terror, in the months after the 9/11 attacks, then-Capt. Jason Amerine was the leader of the U.S. Special Forces team embedded with Hamid Karzai , the future leader of Afghanistan, in Tarin Kowt, the provincial capital of the Afghan province of Uruzgan.

On November 16, 2001, the people of Tarin Kowt rose up against the Taliban and chased them out. A day later Karzai headed into the town in a 20-vehicle convoy and set up shop in the governor's mansion. Arriving around midnight, Karzai met with local Pashtun tribal leaders, who welcomed him and told him with some trepidation that there was a column of some 100 vehicles approaching from Kandahar and containing up to 500 Taliban who would reach the town by the next day intent on taking it back.

The 100-vehicle convoy sent to retake Tarin Kowt for the Taliban was Taliban leader Mullah Mohammed Omar 's last shot at hanging on to power.

Amerine started to plan how to repel the much larger Taliban force, while his combat controller sent out an urgent warning to U.S. Navy and Air Force aircraft in the area that they would be needed shortly.

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Amerine gathered as many of Karzai's guerrillas as he could. His plan was to stake out some higher ground with those guerillas outside Tarin Kowt and call in airstrikes from there onto the fast-approaching Taliban convoy.

Around two hours after Amerine was first alerted to the approaching Taliban column, Navy F/A-18 fighters spotted a group of about 10 four-wheel drives and started bombing them. Three hours later, at 5 a.m., the larger convoy of dozens of Taliban vehicles came into view.

Heavily outnumbered, Karzai's group of Afghan guerrillas took flight and sped back to Tarin Kowt, followed by Amerine and his Special Forces team. Back in Tarin Kowt, Amerine told Karzai, "The Taliban are coming, there are a lot of them. These (Afghan) fighters we are with don't understand our capabilities; they kind of ran. I need to take these vehicles and get out there and keep doing what I'm doing."

Amerine drove back outside the town at around 7 a.m. to direct deadly accurate bombing runs on the approaching Taliban convoy. Three hours later the battle was over, and what remained of the convoy was in full retreat.

Hank Crumpton, who was running the CIA's operation in Afghanistan, recalls that the battle was decisive because Karzai was the only man who could unify the country's fractious ethnic factions: "Karzai was the lynchpin between north and south. The Uzbeks, the Tajiks, the Hazara, they all respected Karzai. They knew that he understood the concept of a nation-state."

But the importance of the Tarin Kowt battle was not well understood at the time because the vast majority of the international media covering the war were concentrated in the north of the country and focusing on the fall of Kabul five days earlier.

Following the news of the debacle at Tarin Kowt, Mullah Omar finally abandoned Kandahar, the city he had controlled absolutely for seven years.

Karzai arrived just outside Kandahar on December 5 to begin the discussions of the terms of the Taliban surrender agreement. The following day, around 9 a.m., the Afghan leader was talking with a local tribal chief when suddenly there was an enormous bang and the doors and windows of the building he was in blew out.

A U.S. investigation later determined that the cause of the explosion was a 2,000-pound American bomb that had fallen 2 kilometers short of its intended target, instead landing on Karzai and his security detail. Three American Special Forces soldiers were killed.

Amerine, who had grown close to Karzai in the weeks he had protected him, was wounded in the leg and evacuated.

Karzai would go on, of course, to become the first democratically elected Afghan President.

Families of hostages have also complained about a lack of communication with them, a lack of coordination between the agencies responsible for securing the release of their family members, and even threats of prosecution if they entered into negotiations with the terrorists holding their loved ones.

The hostage review process, the final findings of which are likely to be made in coming weeks, will surely help to solve some of these problems.

Hunter released a statement in April, saying, "The only government organization seriously developing options to recover Weinstein and others in the Afghanistan/Pakistan region was within the Pentagon -- led by war hero Jason Amerine."

Since the Army is saying little, it is not exactly clear what the grounds are for its investigation of Amerine. That said, it's strange that this officer appears to be being penalized for simply doing the right thing: coming up with novel ideas about how to return American hostages home and communicating with members of Congress who have taken an interest in the issue.