Thomas Pickering explains that the Trump administration’s Iran policy is doomed to fail on its own terms:
The policy of maximum pressure and unachievable demands is based on deeply flawed assumptions about Iran and the wise use of American power.
Pickering is describing Trump’s Iran policy here, but he could just as easily be talking about the president’s handling of many other issues. The Trump administration insists on demanding that other governments capitulate, make sweeping concessions that would overturn most of their current policies, and then punishes them if the other side refuses to comply with insane ultimatums. No one responds well to being dictated to, and that is particularly true of regimes that have made opposition to the U.S. a major part of their reigning ideology. Maximum pressure usually just provokes maximum resistance, and it leads to more of the behavior that the pressure campaign was supposed to stop.
Later on in his column, Pickering reviews the sorry record of U.S.-sponsored regime change and then asks:
When will we ever learn?
If the last two decades are anything to go by, the answer is never. Our policymakers rarely, if ever, learn much of anything from our government’s past blunders and crimes. If they acknowledge that previous policies failed, they are reluctant to admit that the policies were certain to fail. It is much more common for policymakers and pundits to blame the failure of our policies abroad on the inadequacies of our proxies and allies or the designs of our adversaries. The fact that these policies can be undone so easily by obvious and foreseeable problems does not seem to matter. 
There are not many that are willing to accept that a policy failed because it was inherently unsound.
“We” never learn because so many of our political leaders and analysts don’t think that our failed policies were wrong in themselves. The only thing that they are interested in knowing is how to implement the same bad ideas more “effectively” the next time. These are the people that still think that preventive war and regime change are appropriate policy options when done the “right” way. Real learning is impossible without a willingness to question and then discard faulty assumptions, and far too many of our policymakers and political leaders won’t ever get rid of certain assumptions about the U.S. role in the world. Once someone takes for granted that the U.S. has both the right and the authority to meddle in the affairs of other states and dictate their policies to them on pain of collective punishment and/or war, he is likely to see the pursuit of regime change in other lands as being almost synonymous with American “leadership” itself.
https://www.theamericanconservative.com/larison/why-the-u-s-never-learns-from-foreign-policy-failures/