“It’s politics at this point,” said one military official who spoke on the condition of anonymity to discuss policy. He said he thinks the administration does not want to proceed against a high-value detainee without some prospect of civilian trials for other major figures at Guantanamo Bay.

A White House official disputed that.

“We are confident that the reformed military commissions are a lawful, fair and effective prosecutorial forum and that the Department of Defense will handle the referrals in an appropriate manner consistent with the interests of justice,” said the official, who also spoke on the condition of anonymity.

The Defense Department issued a statement Thursday saying the case is not stalled. “Prosecutors in the Office of Military Commissions are actively investigating the case against Mr. al-Nashiri and are developing charges against him,” the statement said.