CHICAGO (AP) — A former California college student accused of attempting to provide material support to terrorists in Syria has invoked a rarely used argument in asking a federal judge in Chicago to dismiss the case on grounds he qualifies for immunity commonly bestowed on soldiers.

Lawyers for the 24-year-old Iraqi refugee, Aws Mohammed Younis Al-Jayab, argue in a motion filed late Tuesday that he hooked up with the kinds of Syrian rebels the U.S. has backed to fight Bashar al-Assad’s regime. Prosecutors have said in earlier filings he aligned with groups that had clear terrorist ties.

His lawyers argue the internationally recognized “doctrine of combatant immunity” prohibiting the prosecution of soldiers can be extended to rebel fighters in conflicts where multiple nations have intervened.

Al-Jayab has pleaded not guilty.