If Several Vietnameese Citys had received the treatment we gave Tokio a coupple of decades earlyer the war would have been shorter so much that the total number of innocents killed might have been much less .
Yes, of course. The best way to avoid needless casualties is to carpet-bomb urban areas. How many Vietnamese would have actually died had the US just walked away, allowed the agreed-upon elections and let the Vietnamese run Vietnam unassisted? The US involvement resulted in the less strident South Vietnamese being wiped out in the struggle, allowing the militant factions of North Vietnam to take over. Over 58000 Americans died in Vietnam, millions of Vietnaese, and nearly every person in that sorry place had his life disrupted, all for nothing.
The horrible mess in Cambodia was a direct result of the US deposing Sihanouk, putting Lon Nol in charge, and since no one liked either Lon Nol for the way he consented to the US carpet bombing of his own country, the coming to power of Pol Pot.
Vietnam was a very, very stupid war. There was no reason for the US to get involved whatever, and its participation made everything worse for all concerned.
McCain, demented soul that he is, still thinks it was a noble cause. Bush thought the same, but it was insufficiently noble for him to risk his privileged neck and he played it safe, defending Texas and Alabama from the Great Enchilada Menace South of the Border. Cheney had "other priorities".