The administration affiliated with the Kurdish-led Syrian Democratic Forces said such a tribunal is needed "for justice to take its course," particularly after countries have refused to bring home their detained nationals. The SDF has captured more than 1,000 foreign fighters, including many from Western countries.
"We don't have other options," Abdulkerim Umer, a foreign affairs official in the Kurdish-led administration, told The Associated Press. "No one wanted to take the responsibility (of repatriating their nationals). We can't put up with this burden alone."
Western countries have largely refused to take back their detained citizens, fearing they would not be able to convict them in civilian courts and that they could pose a security risk. The problem has grown more urgent since President Donald Trump announced his intention to reduce the U.S. military presence in Syria, where American forces are fighting alongside the SDF.
"It is an exceptional situation and we are looking at an exceptional framework," said Ilham Ahmed, the head of the political arm of the SDF, told the AP. "We are dealing with a failed state. In this case we can treat the (Kurdish-administered) region as an exception."
Asked about the tribunal proposal in Washington, U.S. special envoy for Syria and the anti-IS coalition, Jim Jeffrey, said: "We're not looking at that right now." Jeffrey said the priority is to deal with the Iraqi and Syrian prisoners, which he estimated at 7,000 held in eastern Syria and representing the vast majority of those in detention. The second priority, Jeffrey said, is convincing the home countries of the foreign fighters to take them back.
Umer said foreign fighters should be tried where their crimes occurred and where they were detained. "The international community has evaded its responsibility, so we ask that they help us set up the court here," he said.
Germany's Foreign Ministry said in an email that it only knew of the proposal from media reports, but that setting up such a tribunal would "raise many political and legal issues, which would require careful evaluation by the international community."
Germany has said bringing detained German militants home would be "extraordinarily difficult," in response to a U.S. call for European nations to repatriate their nationals. The SDF has been fighting IS since 2014 and has retaken large areas in northern and eastern Syria. Its administration is not recognized internationally or by the Syrian government, which has vowed to bring all the country's territory back under its control.
The Kurdish-led administration has asked the government to grant it autonomy in a new constitution, something Damascus has roundly rejected. Umer said the issue of the foreign detainees is therefore an "exceptional case" that requires an international tribunal. He said the presence of the foreign fighters is a "big problem" that could stoke further instability in the region.
"It is a burden and a risk for us and the international community," he said. Nadim Houry, the director of the counterterrorism program at Human Rights Watch, said "it is hard to imagine" setting up an international tribunal on sovereign territory without that country's approval. Previous efforts to get Security Council backing for international tribunals for crimes committed in Syria have failed, mostly because of vetoes by Russia, a main ally of Damascus.
Houry said a major legal concern would be trying people for the same crimes in different courts depending on their nationality. "There is no real precedent for creating an international tribunal for some nationals and not the others," Houry said. "It is an option that raises as many questions as it provides answers."
He said that while the U.S.-led coalition has provided military aid to the SDF, it has done nothing to help develop the local judiciary. "It is a fair call on the (SDF)'s part to say this should be an international responsibility, but so far the path to such help is unclear."
Kurdish-run courts in northeastern Syria have tried hundreds of Syrians suspected of links to IS. In trials attended by the AP last year, Kurdish authorities showed leniency toward the mostly Arab suspects in a bid to build bridges with the majority Arab population. The courts do not impose the death penalty.
Umer said an international tribunal would help bring the system in line with global norms.
Associated Press writers Frank Jordans in Berlin and Matthew Lee in Washington contributed.