Stalin murders 10s of millions of his own people.
Mao. Murders even more than Stalin.
US "invades" Vietnamese ostensibly (according to its detractors) to prevent Communism from spreading (the domino theory), and the inevitable massacre of civilians which would occur. The later argument was laughed at until the "Killing Fields" became known. (Yes the Khmer Rouge were Cambodian and were put down by the Vietnamese. Good for them!!)
The US props up dictators for all sort of Realpolitik reasons: the same as did/do the PRC (China), the USSR, France, England and all other political powers before (and those that will come). Some dictators (the Shah of Iran were far better than their successors).
And this makes the US the "most violent oppressive nation on earth." Iran, Turkey, Syria (even before the civil war), Saudi Arabia, Pakistan, Myanmar are less oppressive than the US? What!?!
Fuck Bush, Fuck Obama. I say that without fear without the slightest concern that the US government will care in the slightest.
The US isn't perfect, but "the most oppressive?" Are you saying that because you disagree with the Iraq war? Yes, we should have acted differently but what about the mistakes of the UN, Saddam Hussein and Russia in the build up. (The UN by not giving a damn about it's sanctions and lines-in-the-sand being ignored , Saddam bluffing and acting like a blow-hard, and Russia giving Saddam aid and *apparently* moral support, indicating the US was bluffing and wouldn't invade.