What's interesting to me, and shouldn't be surprising, is that there are domino-theory wars like Korea that at least the South Koreans feel benefited them, and

What's interesting to me, and shouldn't be surprising, is that there are domino-theory wars like Korea that at least the South Koreans feel benefited them, and then there are domino-theory wars that didn't really benefit people much. And there are UN-sanctioned things that turned out well, and then there are things like Libya. And the hard part is telling up front which situation you're in... Note that I left off a _long_ list of US military involvement that could not possibly be considered to benefit anything other than maybe US expansion or US business interests. I just listed the ones that might have fit your criteria.