There's growing concern over the proliferation of man-portable air defense systems, also known as MANPADS, and the danger they pose to aviation security. These shoulder-fired, surface-to-air missiles – kind of like a bazooka with a guidance system – are easy to use, easy to transport, and in North Africa and the Middle East, easy to get a hold of.
That's a bad combination in a region that's been wracked by Islamic extremists, like ISIS. According to Defense News, which cited a report from the Small Arms Survey, a Swiss research institute, the instability and looting in Iraq and Libya and general arms trafficking has been blamed for the explosion – pun not intended – of available MANPADS.
"Shooting down a commercial airliner would be consistent with the group's use of increasingly brutal acts to heighten its international profile," a report from the Small Arms Survey, a Swiss research institute read. "To the extent that [ISIS] and its affiliates can obtain access to advanced MANPADS, this represents a particularly acute threat to aviation security."
But the same report indicates things might already be too late. DN reports that extremist forces in both Syria and Iraq "have acquired dozens" of some of the most advanced MANPADS on the market, including examples designed and built by the Russians and the Chinese. Considering that, it's unclear what measures can be taken to prevent another MH17-like disaster.