By Susan Cornwell and Jane Sutton
(Reuters) - With his renewed vow to close the detention camp for foreign terrorism suspects at Guantanamo Bay, President Barack Obama has effectively assigned himself a list of possible ways to take the prison's population down from 166 to zero.
Some would be more easily achieved than others.
In pledging to look again at an unfulfilled promise dating back to his first election campaign and early days in office in 2009, Obama made plain on Tuesday that it was untenable to keep the 11-year-old camp open.
A hunger strike at the camp at the U.S. Naval Base on Cuba began in February, has been joined by 100 of the inmates and has led to force-feedings to keep the weakest prisoners alive, sparking fresh outrage from rights groups over a prison opened under Republican President George W. Bush in 2002.
There were about 245 prisoners at Guantanamo when Obama, a Democrat, took office in 2009 and that has dropped to 166. But releases have slowed to a trickle under restrictions imposed by Congress, including a ban on any of them being brought to the United States. No prisoners have left Guantanamo this year.
Among current inmates, nine have been charged with crimes or convicted, 24 are considered eligible for possible prosecution, 47 are considered too dangerous for release but are not facing prosecution, and 86 have been cleared for transfer or release.
Obama has several options, although it could take a combination of several to clear the camp.
PUT SOMEBODY IN CHARGE
In January, the State Department reassigned the special envoy who had been in charge of trying to persuade countries to take Guantanamo inmates approved for release, Daniel Fried, and did not replace him. That was widely seen as a signal that Obama was giving up on closing the prison any time soon.
Fried arranged for the transfer out of scores of prisoners, but the departures slowed to a crawl after Congress imposed restrictions on them. White House spokesman Jay Carney said on Wednesday the administration was considering naming a senior diplomat to renew the focus on repatriation or transferring detainees.
Christopher Anders, the senior legislative counsel for the American Civil Liberties Union, said such a "point person" was sorely needed as a first step to manage the administration's effort - but that the person should be from the White House. "For the last three years at the White House, it's been like no one home" on Guantanamo, he said.
USE EXCEPTIONS IN LAW TO LET PRISONERS GO
Obama has blamed Congress for interfering with his plan to close Guantanamo. Starting in 2011, Congress began restricting transfers out, saying the Defense Department first had to certify a number of things, including that the destination country was not a state sponsor of terrorism and would take action to make sure the individual would not threaten the United States.
Starting last year, Congress let some restrictions be waived if it was in the "national security interests" of the United States. Obama has not used the waiver or certification provisions.
"For the past two years, our committee has worked with our Senate counterparts to ensure that the certifications necessary to transfer detainees overseas are reasonable. The administration has never certified a single transfer," House Armed Services Committee Chairman Howard McKeon, a Republican, said this week.
The White House could have pushed harder for officials at the Pentagon to process certifications, said the ACLU's Anders.
Wells Dixon, a senior attorney at the Center for Constitutional Rights, a New York organization that has represented a number of Guantanamo prisoners, said Obama could order the Pentagon to begin certifying transfers out. But he also noted potential risks for the president. "There's no political upside" if Obama certifies that a prisoner can leave and then that prisoner later attacks U.S. interests, Dixon said.
SEND PRISONERS BACK TO YEMEN
Congress has prohibited the transfer of detainees to countries with troubled security situations. But the United States could decide that new Yemeni President Abd-Rabbu Mansour has taken adequate measures against al Qaeda and made the country stable enough to resume repatriations to Yemen.
Repatriations were halted in 2010 after a man trained by militants in Yemen tried to blow up a U.S.-bound plane in 2009.
Of the 86 prisoners cleared for transfer or release, 56 are Yemenis. The Yemeni government says it wants them home and is building a facility to hold them for rehabilitation.
That option also has a potential danger - if a repatriated Yemeni eventually attacked the United States or its interests.
USE THE PERIODIC REVIEW BOARD PROCESS
Two years ago, Obama signed an executive order establishing extra review procedures for Guantanamo detainees to determine if continued detention were warranted, but the Periodic Review Boards have not been used.
This option looks fairly simple, since it involves carrying out the president's own executive order. But there may have been no rush to establish more reviews boards since prisoners cleared by earlier review boards are still being held.
USE COURT RULINGS TO GET PEOPLE OUT
Dixon suggested the administration could use court rulings to help get prisoners released. Two members of China's Muslim Uighur minority were resettled in El Salvador in April 2012, four years after a U.S. District Court in Washington ruled there were no grounds to hold them.
When prisoners challenge their detention in federal court, the government could decide not to contest the case, paving the way for a court order effecting the prisoner's release, said Dixon. He said that could happen in any of the more than 100 detainee "habeus corpus" cases filed in federal court.
Obama could instruct the Justice Department to stop contesting those cases.
SEND PRISONERS OUT IN A PRISONER EXCHANGE
The United States tried to work out a deal to transfer five senior Taliban prisoners back to Afghanistan in return for U.S. Army Sergeant Bowe Berghdal, who has been a prisoner of Taliban militants since 2009. The talks were suspended last year. But there will be pressure to return the Afghan prisoners when the U.S. combat mission in Afghanistan ends in 2014.
This option would depend on how relations evolve with Afghanistan. But the Taliban prisoner release plan also met strong resistance among some members of Congress, especially Republicans, who might object if it resurfaces.
CALL ON CONGRESS
The legal restrictions on transfers will expire at the end of the fiscal year, on September 30, so Obama could urge Congress not to renew them - and make clear he considers that a political imperative.
If the restriction on transferring prisoners to the United States were allowed to expire, Obama could not only transfer Guantanamo prisoners to foreign countries, but could bring some back to the United States for trial in federal court.
But some Democrats as well as Republicans argue that bringing Guantanamo inmates to the United States is a security risk. Republican leaders in both chambers have made that a high-profile issue, and Republicans control the House of Representatives.
So the option could be bogged down in Washington politics.
(Reporting by Susan Cornwell in Washington and Jane Sutton in Miami; Editing by Frances Kerry; Desking by Peter Cooney)