Not that I think the US used their earthquake laser on Haiti (we used it on Iran, obvi), but “boots on the ground” is a particularly bad way to determine whether or not “imperialism” is happening. The best imperialists always find ways to get what they want while using their expensive soldiers as little as possible (see for example, “gunboat diplomacy” in “British imperialism in Latin America in the 19th century” and “American imperialism in Latin America in the 20th century”). If you’re occupying a country, ur doing it wrong. The US controlled Cuba via the Platt amendment, after all, not permanent occupation by the rough riders.
By that standard China is shaping up to be a fantastic imperialist power--I mean they rule us just by buying us free and clear! More seriously, they seem really adept at getting other people to do what they want without, you know, any boots on the ground whatsoever. Dudes with money and infrastructure on the ground, sure!
(And I know I should just reply on LGM instead of creating a post over here, but I got nuthin' else today. I could talk about the oil spill getting worse by the day, but you know that.)