Touching upon the failure of the US foreign policy over the past decades, John J. Mearsheimer one of the most important and influential international relations scholars in the world in an interview with Lobelog says, "There is little doubt that most people in the American foreign policy establishment understand that liberal hegemony has been a failure. There is simply too much evidence of failure to defend that policy. Just look at all the murder and mayhem the United States has helped create in the greater Middle East. It is truly stunning how little success the United States has had at spreading liberal democracy into that region. Furthermore, almost everyone recognizes that “engagement” with China has failed, and that although the expansion of NATO and the EU had some initial successes, it ran into a brick wall in Georgia in 2008 and in Ukraine in 2014. The result is poisonous relations between Russia and the West. It is also important to emphasize that when Donald Trump ran for president in 2016, he constantly emphasized the failings of liberal hegemony. And he won the election! Whether the foreign policy elite learns the right lessons from its past mistakes is another matter."
Answering the question about whether Tehran is a direct threat to the United States as many liberal and neocon claim, he said, "Iran is not a direct threat to the United States. It is not even an indirect threat to the United States. First, Iran does not have nuclear weapons and it has signed an agreement with the world’s major powers that makes it impossible for Tehran to develop nuclear weapons in the foreseeable future. Second, Iran does not have missiles that can strike the US homeland. Third, Iran has weak conventional forces, which cannot be used against the United States or any country in the Middle East that is under the American security umbrella. Fourth, Iran is not a serious threat to attack another country in its region. It has not launched a war against another country even once in modern times, and there is no evidence that it is now preparing to take the offensive against any of its neighbors. Fifth, Iran is not the source of America’s terrorism problem. To the extent that any one country deserves that title, it is Saudi Arabia, not Iran."
He went on to say, "The truth is that it is the United States that is a direct threat to Iran, not the other way around. The Trump administration, with much prompting from Israel and Saudi Arabia, has its gunsights on Iran. The aim is regime change."