There is a dispute as to whether U.S. Marines handed over weapons to Houthi rebels or had destroyed them before evacuating the American Embassy in Yemen yesterday.
But there can be no dispute that Iran came out the big winner and the Obama Administration handed them the keys. Iran was further legitimized with Britain and France also evacuating their embassies.
This strengthens Iran's position vis a vis negotiations with the Obama Administration along with the P5 + 1 concerning a nuclear agreement which the Obama Administration is all too eager to obtain.
If the Obama Administration has no problem with Iran taking over Yemen then they are certainly not going to support sanctions against it.
Although U.S. counterterrorism operations will supposedly continue against AQAP they will only continue at the pleasure of the Iran.