Carl Bergen , David Brooks : First American soldier killed while fighting for ISIS . Writers : Other Americans drawn to ISIS , al - Qaeda in Syria ; 100 have fought or tried to . No American involved with ISIS or Nusra charged with plotting attack inside U.S. , they said . Writers : Tracking the foreign fighters is a key priority for our mission .
Peter Bergen , David Sterman : First American known killed while fighting for ISIS . Writers : Other Americans drawn to ISIS , al-Nusra in Syria ; 100 have fought or tried to . No American involved with ISIS or Nusra charged with plotting attack inside U.S. , they say . Writers : Tracking the foreign fighters is a key priority for counterterrorism efforts .