The 2017 National Defense Authorization Act is one of those must-pass pieces of legislation that needs to be implemented every year before the Pentagon can operate in full confidence. Without an NDAA, the world's most lethal military is flying blind.

When you include the annexes, appendices, and the accompanying conference report, the entire package is a massive 3,076 pages. But one section buried in the middle of the bill has the potential to be a game-changer. For the first time in the Pentagon's legislative blueprint, the United States government will be permitted to sell Man Portable Air Defense Systems (MANPADS) to Syrian opposition units that have been vetted by the intelligence community.

The MANPAD exception doesn't at first appear to be a major deal, since President-Elect Donald Trump has let it be known that he isn't especially impressed with the opposition fighters trying to remove Bashar al-Assad's regime. But if by some chance the Trump administration does change its opinion (perfectly feasible, given all of Trump's other policy shifts), it could now direct the Pentagon to provide anti-aircraft missiles under the law as it's currently drafted.