WASHINGTON — A federal appeals court on Tuesday refused to halt the military commission trial of a Saudi national charged with orchestrating the 2000 attack on the USS Cole that killed 17 U.S. sailors.

The 2-1 ruling said that Abd al Rahim al-Nashiri can’t challenge the commission’s authority to hear his case until after the proceeding has run its course.

Al-Nashiri argued that military commissions only have authority over offenses that take place during an armed conflict. He said his actions were not war crimes because the U.S. was not officially at war with al-Qaida at the time of the attack.

But the U.S. Court of Appeals for the District of Columbia Circuit said the military court was capable of deciding whether al-Nashiri’s conduct occurred “outside the context of hostilities.”

Writing for the majority, Judge Thomas Griffith rejected arguments that the appeals court should consider the challenge now because al-Nashiri was subject to torture while in U.S. custody. Al-Nashiri was held for several years in secret CIA prisons after his capture in 2002.

Authorities have disclosed that he was subjected to a mock execution and waterboarding. Al-Nashiri says he was also hung by his hands, deprived of sleep and regularly beaten. He was transferred to the prison at Guantanamo Bay in September 2006.

“Al-Nashiri’s allegations regarding his treatment during detention, while deeply troubling, do not provide any reason to fear that he will not be given a fair hearing in the military commission,” Griffith said.

In dissent, Judge David Tatel said evidence that al-Nashiri was tortured while in U.S. custody warrants considering his claims now. If allegations about his treatment have merit, “the alleged burdens he faces are not only unusual, but extraordinary,” Tatel said.

Al-Nashiri argued that he was subject to years of brutal interrogation tactics by the same executive branch that now seeks to try him. He said he suffers from psychological disorders that will be aggravated by trial before a military commission.

Al-Nashiri faces a possible death sentence if convicted of planning and preparing for the attack, which took place off the coast of Yemen. The government says the Cole was bombed by two al-Qaida operatives who set off explosives as they pulled their fishing boat up to the destroyer.