RACHEL MARTIN, HOST:

President Trump has signed an executive order to keep the U.S. military prison at Guantanamo Bay, Cuba, open. It was a key campaign promise, and the president made this announcement during his State of the Union speech last night.

(SOUNDBITE OF 2018 STATE OF THE UNION ADDRESS)

PRESIDENT DONALD TRUMP: I am asking Congress to ensure that, in the fight against ISIS and al-Qaida, we continue to have all necessary power to detain terrorists wherever we chase them down, wherever we find them. And in many cases, for them, it will now be Guantanamo Bay.

MARTIN: The move repeals part of the executive order signed by his predecessor, President Barack Obama, who called for the prison to be closed after he took power back in 2009. NPR national security correspondent David Welna is with us now.

Hey, David.

DAVID WELNA, BYLINE: Hey, Rachel.

MARTIN: So President Obama tried to close Gitmo for years. He never succeeded. The prison is still open. So what does President Trump's action actually change?

WELNA: Well, not a whole heck of a lot, Rachel. There are still 41 prisoners there. That's down from close to 700 during the Bush administration. And while both Presidents Bush and Obama had policies aimed at shutting the place down, Trump's executive order makes clear he has no intention of doing so. I spoke with Lee Wolosky about that order. He was Obama's special envoy at the State Department for closing Guantanamo. And he says it could have serious consequences for counterterrorism efforts. Here's Wolosky.

LEE WOLOSKY: There are partners of the United States who will refuse to turn over terrorism suspects to the United States if they believe that they will end up in Guantanamo. And there are partners of ours on whom we rely to gather intelligence against extremist groups who have told us repeatedly that Guantanamo inhibits their ability to cooperate with the United States.

MARTIN: You know, David, President Trump - we heard him pledge that he was going to fill Guantanamo with terrorists, so-called bad dudes. The administration, though, has actually not added any new prisoners, right? How come?

WELNA: Well, you know, I think that could be because Trump has come to realize that Guantanamo has been pretty much a dead end when it comes to trying and convicting accused terrorists and that U.S. civilian courts have been a lot swifter and effective in convicting hundreds of accused terrorists. But the question now is whether he's going to add any, on the recommendation of Defense Secretary Jim Mattis, which he's requested.

MARTIN: What happens to the detainees who are currently cleared for release?

WELNA: Well, there are five of those detainees whose continued detention was found by half a dozen federal agencies, including the Pentagon, to be no longer necessary. But they were not yet transferred to another country at the end of the Obama administration, so it looks like they're stuck there along with the 36 others.

MARTIN: All right. NPR national security correspondent David Welna for us this morning. Thanks so much, David.

WELNA: You're welcome, Rachel.

(SOUNDBITE OF STEV'S "WHILE YOU'RE FADING") Transcript provided by NPR, Copyright NPR.