Who is arming the Syrian rebels?

Human rights activists and military affairs analysts have all concluded that Syria is awash with weapons. It will take years to bring the spread of weapons inside Syria under control. The availability of weapons in Syria is not a safety problem for Syrians after a settlement is reached, it will be a problem of all neighboring countries, especially Jordan, Lebanon, and Turkey.

The New York Times compiled a record of cargo flights believed to be supplied to the rebels show that Syria might be the country with most weapons in the hands of non-governmental agencies at this time.

New York Times compilation of weapons heading to Syria: An Arms Pipeline to the Syrian Rebels