Decades of distrust and enmity have defined America’s relationship with Iran, making it one of our most difficult foreign policy challenges.

Recently I met with mid-level military officers from around the world who were visiting the U.S. In that meeting, and in similar meetings with diplomats and foreign ministers, I have been impressed with the focus on a single topic: the competition between the United States and China.

Russia keeps inserting itself into the world’s conflicts, exerting outsized influence in the Middle East, Europe and elsewhere. How much of a threat does it pose to the United States? And what should we do about it? These questions are at the top of our foreign policy agenda.

The war in Afghanistan, the longest war in American history, has dragged on for over 17 years. It has claimed thousands of American lives and cost trillions of dollars. And to what result?

Not so long ago, Americans thought of threats to our nation in terms of armies marching across borders, nuclear weapons in the hands of our enemies, missiles aimed at our homeland and 9/11 style terrorist attacks.