The U.S. Was Resettling Guantánamo Prisoners. The Hamas Attack Halted Those Plans.

The Biden administration was poised to send about a dozen detainees at Guantánamo Bay to Oman for resettlement last year, but it abruptly halted the secret operation amid questions from Congress about security in the Middle East after Hamas attacked Israel, according to administration officials.

None of the prisoners have ever been charged with crimes, and all of them had been cleared for transfer by national security review panels.

A military cargo plane was already on the runway at Guantánamo Bay ready to airlift the group of Yemeni prisoners to...