You're obviously exaggerating and then some. Most of what you're claiming is fraudulent.
Show me when the US "flattened" Laos and Cambodia: show me the specific, vast invasions, the war details, and the numbers of people that said US wars killed in those nations. You're inventing history. Pol Pot's regime flattened Cambodia, murdering millions of his own people.
The truth you're intentionally evading, is that Asian nations have done drastically worse to each other and or their own people in the last century than anything America has done in the three primary wars the US has been involved in there (all of which were wars of defense/response; defending South Korea, defending South Vietnam, trying to stop the wars of the Empire of Japan). Most of the deaths in the Vietnam civil war as an example, were Vietnamese people killing each other (witness what happened when America left: vast indiscriminate slaughter by the North of the South).
North Vietnam started the war of conquest on the South, which the US attempted to stop. Just as North Korea attempted to enslave South Korea under Communism by military means (and would still like to conclude that 'reunification').
The US expended vast sums of money and blood to keep South Korea from the outcome that North Korea has seen. While China was rotting under Mao, South Korea was being protected and economically nurtured, becoming a first world nation while China and most other nations of Asia were still third world economically (for these purposes, third world meaning the level of economic development, not the definition based on alliance).
The US has protected Japan for 70 years, while they maintained a pacifist constitution. We were far more civil with them post war (a war they started), than what your claims imply we would have been. We didn't hold them as a slave nation, instead they rapidly re-industrialized and ended up passing the US in GDP per capita by the 1980s. We should have nuked them in WW2; they started multiple wars of conquest in the Pacific that resulted in the genocide of millions, including aligning themselves with Hitler's Axis, declaring war on the US and attacking the US. The alternative was to lose hundreds of thousands of American soldiers invading Japan (and one nuke was not enough, they refused to surrender, which logically demonstrated their resolve). The nuking of Japan, or the fire bombing of Tokyo, was no worse than the fire bombing of Germany.
The US also shielded China from being nuked by the USSR [1]. Then we invested extraordinary sums of capital into their economy, providing the economic seed - through mutual trade - that has made their present outcome possible. It was, in part, Nixon's political efforts that helped to open China to the world as a society through trade. Further, given the extreme advantage the US held post WW2 (in every possible regard), it could have attempted to conquer China (or if it were consistent with your false premise: the US could have slaughtered China with nukes), using Japan as a launching point. The US did nearly the exact opposite instead.
The US didn't hold the Philippines, Japan, South Korea, South Vietnam, etc. as conquered territories (it could have attempted it).
Meanwhile, in America, Asians have the highest standard of living of any demographic: they have the lowest crime rates, the highest employment rates, the highest median incomes, the highest household incomes, the highest median net wealth levels, the highest education levels, the longest life expectancy.
[1] http://www.telegraph.co.uk/news/worldnews/asia/china/7720461...