On Wednesday, Mr. Hagel disputed that claim. He said that the former detainees “have not been implicated in any attacks against the United States, and we had no basis to prosecute them in a federal court or military commission.”

Later, however, under questioning by Representative Mac Thornberry, Republican of Texas, Mr. Hagel conceded that even though there was no evidence of “direct involvement” in attacks on American troops, the detainees had nevertheless been “combatants” in the armed conflict because, as mid- to high-ranking members of the Taliban government, they were involved in “planning” Taliban operations.

Mr. McKeon said, “Bin Laden didn’t pull the trigger, but we went after him because he caused 9/11.”

Sergeant Bergdahl was held in Pakistan by the Haqqani network, a group aligned with the Taliban that the State Department has listed as a foreign terrorist organization. On Wednesday, several Republican lawmakers asked Mr. Hagel to explain why the prisoner swap did not violate the United States’ longtime policy of not negotiating with terrorists.

Mr. Hagel said that the Obama administration was not negotiating with terrorists because it had dealt directly with Qatari officials, not militants, and that the Qataris were talking to the Afghan Taliban, who have not been designated as members of a terrorist organization.

Several lawmakers were not satisfied.

“These responses are very, very tortuous,” said Representative John Kline, Republican of Minnesota.