Actually President George W. Bush’s preëmptive War in Iraq spelled the end of regime change in America. At least in the sense that America would unilaterally invade and occupy another country to knockout the authoritarian regime there and replace it with a new government. Some people might point to Libya to contradict that, but Libya was an international effort where the Europe played a large role in knocking out the regime there. After two or three years of trying to stabilize a country that wasn’t ready to be stabilized because it didn’t have a government that could govern and defend the country, Americans were fed up over Iraq. And as a result non-interventionist Democrats came to power in Congress in 2007 that were perhaps led by Barack Obama and Barack Obama becomes President in 2009.
The official ending of the Vietnam War ended in 1975 and the fortieth anniversary is this year. And there are so many lessons from that war that people especially Neoconservatives on the Right who think interfering in other countries affairs is a good idea, that they haven’t bothered to learn. The biggest lesson I believe is don’t try to fight for people who won’t fight for themselves. We’re not going to send in ground troops to a country to fight for people who won’t fight for themselves. At least since 2009 and even if the next president is a Republican, which is not likely they’re going to have a real hard time getting the country and Congress whoever controls it to back them. If the people in that country won’t fight for themselves.
You don’t see a lot of even Republicans adopting President Bush’s preëmptive war policy. Not even for North Korea which is a bigger problem even now than Iraq ever was and the same thing with Iran. Because at least Iran unlike North Korea has something that looks like a functioning economy where at least the people there can feed themselves for the most part. And this is all because Americans are tired of fighting and paying for other countries wars. For America to help other countries militarily deal with either their own government or a terrorist threat there, the people on the ground have to be willing and able and then do the fighting themselves. Before America will assist them which is why preëmptive war is dead as an American foreign policy.