Since he first ran for office, Barack Obama has made closing the terrorist detention facility at Guantanamo Bay a top priority.

When Congress refused to pass legislation that would have shut down the prison, Obama threatened to close the facility through executive order.

But Obama just admitted defeat on what was one of his signature issues.

New reports state Obama has now ruled out closing the Guantanamo Bay prison facility through executive fiat.

Reuters reports:

The Obama administration is not pursuing the use of an executive order to shutter the Guantanamo Bay military prison after officials concluded that it would not be a viable strategy, sources familiar with the deliberations said.

The conclusion, reached by administration officials, narrows the already slim chances that President Barack Obama can fulfill his pledge to close the notorious offshore prison before leaving office in January.

The White House has said repeatedly that Obama has not ruled out any options on the Guantanamo center, which has been used to house terrorism suspects since it was set up in 2001 following the Sept. 11 attacks on New York and Washington.

Obama is eager to fulfill his 2008 campaign pledge to close the prison and could still choose to use his commander-in-chief powers, but the option is not being actively pursued, the sources said.

Without executive action, the chances of closing the prison would hinge on convincing a resistant Congress to overturn a long-standing ban on bringing possibly dozens of remaining prisoners to maximum-security prisons in the United States.

While Obama’s scheme to close Guantanamo Bay’s terrorist detention facility has been thwarted, there are still 30 prisoners in the facility that are scheduled to be transferred to other countries.

And this represents a threat to our national security.

647 detainees have been released from Guantanamo Bay and nearly 20% have returned to terrorism.

CNS News reports:

“The Director of National Intelligence released a report this week indicating that the United States has “confirmed” that 116 detainees “transferred” out of the prison at Guantanamo Bay, Cuba, subsequently reengaged in terrorist or insurgent activities.

The report also warned: “Based on trends identified during the past eleven years, we assess that some detainees currently at GTMO will seek to reengage in terrorist or insurgent activities after they are transferred.”

The DNI first publicly warned more than four years ago–in December 2010–that the number of then already “transferred” Guantanamo detainees returning to terror and insurgent activity would increase as time passed and that if additional detainees were released in the future some of those would also return to terrorist and insurgent activities.”

These numbers likely contributed to the lack of Congressional support for an executive order to close down Guantanamo Bay’s terrorist detention facility.

In addition, Obama likely would have faced a lawsuit over an executive order, because closing the prison requires Congressional approval.

And even his own Attorney General says it is illegal to transfer prisoners held at Guantanamo Bay to U.S. soil.

So for once, Obama backed down rather than use executive orders to end-run Congress.