washington two u.s. f-22 fighter aircraft fire warn flare wednesday two russian su-25 jet enter agree upon deconfliction area airspace east euphrates river syria u.s. military say eric pahon pentagon spokesman say f-22 aircraft provide air cover partner grind force russian jet come airspace near albu kamal incident last 40 minutes coalition officials contact russians communication link avoid miscalculation one point pahon say russian jet come close enough one f-22 aircraft aggressively maneuver avoid midair collision u.s. officials say battlefield islamic state shrink expect russian u.s. aircraft close proximity since early november russian jet fly east euphrates river deconflicted airspace six eight time day accord u.s. military become increasingly tough pilot discern whether russian pilot action deliberate honest mistake pahon say coalition great concern could shoot russian aircraft action see threat air grind force add u.s. defense secretary jim mattis say u.s. military fight islamic state syria long want fight describe longer-term role u.s. troop insurgents lose territory control u.s. jet fire flare warn russian jet syria