are now on the ground in northern syria supporting a combination of rebel forces? reporter: more u.s. troops arriving in northern syria, jake, and it s no mystery. more u.s. troops, more risk. the american flag flying, 100 army rangers in combat vehicles are in open ground in dangerous northern syria near a town called man bidge. why talk about it when president trump is worried about signalling military moves? the troops want everyone to know they are there. their job, be a buffer to keep kurdish, syrian, turkish, russian, and local forces from fighting each other. not visible, as many as 400 marines are also moving north of raka, the next major battle. raka is itself a declared capital. the top u.s. commander is ramping up the pressure for an attack against the 4,000 isis