Washington — Sgt. Bowe Bergdahl is to appear this month at the next hearing in his court-martial at Fort Bragg, N.C. After Sergeant Bergdahl walked off his Army outpost in Afghanistan in 2009, he was abducted and tortured by the Taliban, who subjected him to nearly five years of harsh captivity.

Sergeant Bergdahl faces charges of desertion and misbehavior before the enemy, yet two senior military officers conducting separate, impartial investigations into his case have recommended no imprisonment. That outcome would be consistent with hundreds of other post-Sept. 11 desertion cases.

But that does not sit well with certain politicians who have treated Sergeant Bergdahl’s case as if it were a political piñata. Foremost among them is Senator John McCain of Arizona, chairman of the Senate Armed Services Committee.

In March 2015, the Army warned the committee that holding any congressional hearing on Sergeant Bergdahl could undermine military justice. Two months later, after a senior McCain staff member raised the prospect of the senator’s doing just that, an Army official repeated the warning against holding such a hearing. “To do so,” he added, “would be unprecedented and deviate from defense oversight committees’ longstanding practice of deference to allow ongoing military justice matters to proceed to completion without direct congressional involvement.”