George W. Bush sent troops to Iraq to impose liberal democratic values and create a model state for the Middle East. Thousands of Americans, and hundreds of thousands of Iraqis, lost their lives as a result. Iraq predictably wound up as a ramshackle democracy and an Iranian client state. It was a disaster.
When Qaddafi threatened to exterminate Libyan rebels, our European allies persuaded a somewhat reluctant Barack Obama to assist the insurgents with air power. The campaign was a military success, and the government was toppled, but no one had a viable plan for what came next. The country is still engulfed in a civil war. It was a disaster.
When the Arab Spring came to Damascus, neither Obama nor Trump was willing to provide any meaningful military assistance to the rebels. Assad, with lots of foreign help, turned his country into a pile of rubble. Hundreds of thousands died, and millions left, destabilizing the area and European politics, to boot. It was a disaster.
Both Obama and Trump, albeit for slightly different reasons, have supported the Saudi war in Yemen. It has created a humanitarian disaster for minimal geopolitical gain.
What is the message from this? Your first response is probably to stay out of the Middle East altogether, and there is something to that. The real lesson, however, is to stick to our core mission of preventing terrorism and keeping the oil flowing, and to avoid any big military or political projects. That is a reasonably limited goal, and is achievable.