the weapons and ammunition are usual from east Europe (Bulgaria, Serbia, Croatia, Ukraine ...)

the contracts are with U.S. companies themselves hired by the CIA and/or Pentagon as well as with Saudi and Israeli companies

offloading during unusual "fueling stops" allowed to disguise the real addressee of the loads

With lots of details from obtained emails.

Ten thousands of tons of weapons and ammunition to al-Qaeda and other Takfiris in Syria also came first from Libya by ship, then on at least 160 big cargo flights via Saudi Arabia and Qatar to Turkey and during the last years by various ships under U.S. contracts from mostly east-European countries.

With all the Trump-Russia nonsense flowing around one person's involvement in the creation of the issue deserves more scrutiny:

McCain and the Trump-Russia Dossier: What Did He Know, and When? - Reason

A British spy. An Arizona senator. And one inflammatory dossier on Donald Trump. The connection between them is starting to unravel...