Stratfor has a very interesting piece out, discussing how weapons’ durability, interchangeability and stable value means that they will flow from one conflict area to another, and from one actor to another, meaning that any “we’re arming the good guys” (no matter how those are defined) is pretty meaningless in terms of final outcomes.
The paragraph that made me do a double take was this one:
One of the functions of the U.S. presence in Benghazi, Libya, was to help facilitate the flow of Libyan arms to Syrian rebels. From the American point of view, sending weapons to Syria not only helps the rebels there, but every SA-7b shoulder-fired surface-to-air missile sent to Syria to be fired at a regime helicopter or MiG fighter is one less missile that can find its way into the hands of militants in the region. Promoting the flow of weapons out of Libya to Syria also makes weapons in Libya much more expensive, and can therefore reduce the ability of local militia groups — or regional militant groups such as al Qaeda in the Islamic Maghreb or Boko Haram — to procure weapons from Libya.