What if the USA had invaded North Vietnam? IOTL, they didn't due to fears of Chinese intervention, but what if the USA just, well, gets over these fears? As in, it seems as if the Chinese are distracted and the USA thinks they won't intervene(like a worse Sino-Soviet Crisis), or the USA reaches some sort of earlier diplomatic deal with China, like what Nixon and Mao did? How would the invasion of North Vietnam go? Would it be enough to win the war?