The Obama administration has launched a renewed effort to winnow the remaining detainee population at Guantánamo Naval Base, according to lawyers who have long represented them.

On Friday, the last Kuwaiti captive still held at Guantánamo was returned to his home country, where he will be subject to special rehabilitation and security measures. On Jan. 6, the U.S. flew two Yemeni detainees held for nearly 14 years to Ghana. Both of the Yemenis had been cleared of posing any threat to the United States by an interagency panel six years ago.