> the people held at Guantanamo are responsible for killing humans via cowardly terrorists attacks, either indirectly or directly.
The people held at Guantanamo Bay are not considered POWs by the US, nor have they been given a trial. They're held in violation of even US law. The US has let some go saying they picked up the wrong person. Who determined they are responsible for what you say they are responsible for? Even the US doesn't agree as they say they picked up some in error and let them go.
On top of this - for over half a century the country of Cuba has demanded the US withdraw its military base from Cuban territory. As US presidents piously intoned about Russian troops in Donetsk, that a sovereign nation wants US troops out of its territory is considered so unimportant it is practically unknown.