AMCD advisor, Dr. Walid Phares writes in Independent Arabiya. 

English summary:
The piece retraces the history of confrontations between the US and Iran regime since Carter and Reagan, noting the grave mistakes of the Obama Administration that led to the lionization of the regime and its military expansion. Under Trump the US is determined to contain and reverse Iran’s regional expansion.

What triggered this last cycle was the rapid proliferation of missiles and the aggressive advances of Iran’s militias across the region. The Trump Administration moved fast from withdrawal from the deal, sanctions and designations. Tehran responded with use of missiles against the Gulf, sabotages and drones. Washington deployed forces and weapons to the region. 

Iran’s leaders realize they are playing with determined US leadership. If they back off, their regime will be in trouble. If they decide to strike, they could lose their main armed forces. The Ayatollahs’ regime seems to be out of options. They are left with two options. Talk or wait for 2020’s election.