Anne W. Patterson: “Iran is not open for business and the American government will do everything it possibly can to enforce these sanctions.”

Our differences with Russia, Iran, and the Assad regime are very substantial, but the benefits of ending this conflict are even greater.

We don't believe it is possible to have any sort of settlement there, either a political settlement or any military defeat of ISIL, without the departure of Assad.

Certainly our European allies, our Gulf allies, and Turkey do see that. They are absolutely determined that he will not remain in power.

To protect U.S. interests amidst this volatility, we have to recognize and cope with the challenges that states across the region face.