The US has a long history of fomenting regime change in other countries. Most infamous are probably the overthrows of democratic governments in Guatemala (1954) and the 1973 overthrow of Allende in Chile. But there were many more.
In this post I want to investigate the effects of those regime changes.
Regime changes work best - from the point of view of power politics - when the resulting regime stays dependent on the US for its survival. This can take different forms:
- one is that of the dictatorships in the Third World. Those guys knew that without US support their long position was dubious in the long term. So they took care to stay friends with the US and support its policies. As nowadays dictatorships are out of fashion in the West this model no longer applies. Some vestiges remain: the US will not openly criticize its dictatorial friends (like Bahrain) and it is more tolerant when friendly semi-democracies (like Georgia under Saakashvili) violate press freedom or otherwise tries to bend the democratic rules than with countries it doesn't consider friends.
- then there are the countries that for their survival depend on the US. This applies to Kosovo and Israel. The result is a strangely perverted relationship where the US seems to encourage its client to behave irresponsibly so that it stays dependent on the US. In Israel this happens with a far going indulgence towards Israels mishandling its Palestinians. In Kosovo we see a complete ignoring of the position of the minorities while the most obvious solution (border changes) is actively obstructed by the US. I don't believe this is intentional. It looks more like the behavior of some parents whose children stay dependent on them long after they have passed 20.
- a third category are the losers. Thieu in South Vietnam and Karzai in Afghanistan are the best examples. The US has installed them but they don't have it in them to become an effective ruler. They don't have clear goals and instead allow the circumstances to dictate their actions. They see allowing corruption and incompetence as means to keep their underlings happy but they feel threatened by competent underlings and will undermine them. From the point of view of US power politics they are clients from hell: they need permanent support, yet replacing them is impossible as they don't allow alternative power structures to arise.
- a related problem happens is the anarchic situation. Where in the previous situation there was one ruler with too little power base there are here too many politicians with each their own power base. This typically happens when the US has brought the rulers to power. Think of Afghanistan after the departure of the Russians, Iraq after the departure of Saddam or Libya after the departure of Gaddafi. The US can try to appoint someone or try to get the different leaders agree on a way forward. But typically you end up with a lot of unresolved issues and smoldering power struggles. Building a state from the ground up is fundamentally different from continuing from a status quo. But US leaders usually prefer pummeling enemies above making a compromise with existing powers. And so while in Iraq it would have been preferential to have a compromise with the Sunni's and in Libya a compromise with Gaddafi would have contributed to stability the US preferred to humiliate its (imagined) adversaries to the bottom - with dire consequences. It looks like the US is doing the same with Syria.