Britain should take care of the mess that was their citizens, not us. I feel this is not our responsibility.  Since this hinges on an obama proclamation I feel that should be wiped clean.

Justice leaders wary to try ISIS fighters in US, as prosecutors push for case

"WASHINGTON - Justice Department leaders are reluctant to recommend U.S.-based criminal trials for two Islamic State militants captured and detained in Syria, according to American officials who said that, even though federal prosecutors believe they can win in court, it is unclear whether there is sufficient evidence to secure convictions and lengthy prison terms.

At the same time, senior Trump administration officials are adamant that Britain bears responsibility to prosecute the men, Alexanda Kotey, 34, and El Shafee Elsheikh, 29, whose British citizenships were revoked over their alleged affiliation with an ISIS cell suspected of murdering Westerners.

Further complicating matters, Attorney General Jeff Sessions would prefer that Kotey and Elsheikh be sent to the U.S. military detention facility in Guantanamo Bay, Cuba, though he has recognized the success of federal terrorism prosecutions.

State Department officials are wary of undermining the U.S. government's position that terrorist fighters captured overseas should be returned to their countries of origin. ...."

"A presidential directive signed by President Barack Obama in 2015 states that the prosecution of hostage-takers is an important deterrent. The U.S. government, it said, shall seek to ensure they are prosecuted through "a due process criminal justice system" in the United States or abroad."

https://www.lmtonline.com/news/article/Justice-leaders-wary-to-try-ISIS-fighters-in-US-12910015.php