Everything is about proxy-empires now: consider the Warsaw Pact - none of those nations were annexed directly by the Soviet Union, it was more cost effective to install puppet governments. America uses the same tactic: it was much cheaper to use a CIA propaganda campaign to overthrow the democratic Iranian regime in 1954 and put the dictator in power than it would have been to invade the country. One thing about "countries" not occupying others isn't quite true - countries generally turn a blind eye to each other's colonial conquests, and they get assimiliated as part of the host country - e.g. Hawaii was only invaded by America just over a century ago. It ceased to exist as a sovereign nation. But you can't really claim it isn't occupied by force (and outbreeding the natives, importing white settlers).
Considering that situations in which America has overthrown democratic governments (and placed or propped up genocidal maniacs), actually vastly outnumber the times that America intervened to protect democracy in a nation, I'm highly skeptical that humanitarian issues are America's primary concern. I can't really think of
any examples that would truly qualify.
It seems like people are drinking the koolaid when they talk about America unilaterally "destroying monsters" around the world - most of the time, the monsters they destroyed were their own creation (who do you think was selling oil to Japan prior to WWII? Texas). I could make a list of genocidal regimes back by the USA since after WWII, but i don't think this forums allows so many words per post.
I'll just point out, that America, materially and politically, backed Pol Pot as the legitimate leader of Cambodia, one of the last century's most genocidal figures.
http://www.thirdworldtraveler.com/US_ThirdWorld/US_PolPot.htmlActually, that's the Reagan Era, in a nutshell - they created or supplied Al Aqaeda Terrorists in Afghanistan, Pol Pot's Terrorists in Cambodia, Contra Terrorists in Nicaragua, etc, etc. Seems to have been a "thing" the Reagan Administration was into, create Terrorists to plague unfriendly nations, create Death Squads to "police" friendly nations (the El Salvadorean death squads and the Colombian UAC being prime examples, their atrocities are literally straight out of the School Of the Americas training manuals).