Khaled Abdullah/Reuters
Police troopers stand on a police truck positioned at a checkpoint in Sanaa February 15, 2015. Tens of thousands of Yemenis demonstrated in several cities on Saturday against the rule of the Shi'ite Muslim Houthi movement as clashes between Houthis and Sunnis in a southern mountainous region left 26 dead.
The US has delivered military aid to San'a that includes 200 M-4 rifles, 160 Humvees, a CN-235 transport aircraft, and two coastal patrol boats, the Post reports.
Pentagon sources told the paper that the that equipment isn't missing, per se - but that the US isn't quite sure of where this materiel is or what it's currently being used for.
Yemen's government collapsed in January, a few weeks after Houthi rebel militants first entered the capital and began stripping away Yemen's already weakened state institutions. The Houthis, a Shi'ite tribal group from the country's lawless periphery, harbor a number of longstanding grievances towards Yemen's Sunni-dominated central authorities.
But the movement is Iranian-backed, and its success in derailing Yemen's post-Arab Spring transitional government was yet another instance of Tehran successfully leveraging - and in the process worsening - a general breakdown in regional order.
The Post report highlights the extent of the US's strategic backsliding in the country, whose recently-ousted president was one of the most cooperative American counter-terror partners in the region. The US spent $500 million building a military in an unstable and strategically critical Middle Eastern country - and because of an Iranian-backed group, a government in which the US had invested hundreds of millions of dollars doesn't event exist anymore.
The US has encountered into similar problems in Iraq, where ISIS looted American weaponry from retreating Iraqi troops during its blitz through the country in the summer of 2014 - and where Iranian general Qassem Suleimani was recently photographed surrounded by Shi'ite militants toting American-made guns.
Yemen is yet another instance in which the US attempted to build state capacity on behalf of a government that couldn't survive the region's chaos. A half-billion dollars worth of US-made military equipment may be floating around the Middle East as a result.