The US Justice Department said Thursday that it brought home 27 Americans who went to Syria and Iraq to join the Islamic State group, as Washington again urged other nations to do the same.
A day after filing charges against a Trinidadian-American father and son who enlisted in the Islamic State in 2015, the department said it had brought criminal terrorism support cases against some of those returning Americans.
Washington has said it is setting an example for other countries, notably Britain and France, who have resisted repatriating perhaps hundreds of their nationals from Iraq and Syria.
"This was our moral responsibility to the American people and to the people of the countries to which these terrorists traveled," said Assistant Attorney General John Demers in a statement.
The 27 represent only a portion of the hundreds of Americans and thousands of citizens of other countries who, often with their families, enlisted in the Islamic State as it undertook a bloody campaign to establish its "caliphate" across Syria and Iraq six years ago.
Many remain in camps in Syria under the control of the Syrian Democratic Forces.
Demers said that they had repatriated all 27 "against whom we have charges," suggesting there could still be more, as cases are built against them. He did not offer details on the accusations.
After wrestling with whether to abandon US "foreign fighters" for Islamic State in the region or to move them to the US military's Guantanamo prison camp, Washington decided two years ago to try them in federal courts.
Those charged with "material support of a designated terrorist group" include Kazakhstan-born, naturalized US citizen Ruslan Maratovich Asainov, 44, who was called an IS sniper and weapons trainer.
Also charged was Texas-born Omer Kuzu, who as a 17-year-old went to Syria with his brother in 2014 and worked as an IS communications specialist before his capture last year.
Some US allies have balked at bringing home their nationals.
London has refused to try El Shafee Elsheikh and Alexanda Kotey, two men from Britain who are tied to murders of US and British journalists and aid workers as part of a notorious Islamic State kidnapping cell dubbed The Beatles.
Instead, Washington is now preparing the transfer them to the United States for trial.
Washington has been pressing hard the repatriation issue, vetoing on August 31 UN resolution pushed by Indonesia on handling foreign fighters because it didn't demand countries act to take back their own.
On Thursday the State Department praised Italy for repatriating one of its citizens to stand trial for supporting Islamic State.
"Repatriating and prosecuting terrorists is the most effective way to keep them from returning to the battlefield," Secretary of State Mike Pompeo said.
"The United States should get credit for practicing what it preaches in regards to bringing back citizens to face justice," said Seamus Hughes of the George Washington University Program on Extremism.
But he added that the "material support" statute used by US authorities has a "comparatively easier threshold" for charges and convictions that laws in Europe.
Moreover, he said, the number of European foreign fighters is far higher than Americans, and so a much larger challenge.
Some US material support cases have been criticized for overzealousness.
One of the earliest, Samantha Marie Elhassani, was charged in Chicago federal court with material support for a designated terrorist group in 2018.
But she claimed that she and her two children were forced to go to the Syrian warzone in 2015 by her husband.
Her lawyers were able to get a reduced charge, providing financial support for the terror group, because she admitted carrying money to Hong Kong for her husband. But she still faces a possible 10 year prison sentence.
"For the politics of the war on terror, they have to somehow turn them into ISIS members," said Thomas Durkin, a Chicago attorney in the Elhassani case, said of some Justice Department cases.