It'll be interesting to see how he gets them in theater. If it's by ship, then they'll have to steam through the Bosporus Strait, right through the center of Turkey's capital. I don't really know if Turkey would allow that.
Otherwise, they'd need to travel down through the Caucasus mountains (Georgia, Armenia, Azerbaijan) and into Iran and then Iraq... before finally reaching Syria.
And if they fly in... well, that'll take an epic number of flights. Passenger jets hold about 200-600 per flight, so using the largest planes, we're looking at 250 flights just for the personnel alone.