JL- Nixon was nop planning the use of nukes. The context was that they were an option. Just as they are in Afghanistan. Ok, this is how it went. Eisenhower warned Kennedy against the use of troops in Vietnam. Kennedy, as I said earlier, totally misunderstood what was happening. The VC weren't looking to take over the Phillipines or Thailand, their concerns were more local. The "domino effect" was never an issue in reality, but in perception it was. Kennedy escalated the efforts until he was assassinaed. Johnson, who was never meant to be president, found himself in a situation completely out of his depth. He contiued the effort and swelled troops to the highest level because.
1) at first he thought he could win.
2) Bobby Kennedy et al.
Johnson was a savvy political animal and the Kennedys were a force he did not want to cross. The Kennedys did not want JFK's vision of a communist free south asia to be ruined by some half witted Texan hack (no disrespect to Texans 🙂 ). So, acting on bad advice and self preservation, he increased numbers until it was clear that ironically, the US might just win. Now the fear here was that China might intercede in this case, and China certainly was unstoppable on the ground. They could mobilize millions of soldiers to march right in. That would leave us no choice but to surrender or nuke them. WWIII. LBJ wasn't a genius, but knew that was an untenable situation. So he was stuck. He could not withdraw, and he could not win. A stalemate of our own creation. This is why we had those silly rules of engagement. Worse for him, the anti war movement started in earnest. The forces opposed to the war were gaining strength. Now comes Nixon. He certainly did not want this can of worms. However with the presidency, comes the headaches of the previous administration. Nixon had something horrible happen that did finally force an end to the stay/go stalemate. Kent State. This really was the nail in the coffin for the war. At this time the tide turned so much against the war that Nixon had to find the "peace with honor" solution that was really a fancy surrender. At no time did Nixon seriously consider nuking Vietnam more than any other president. Also remember the war was practically over when he was forced from office, so that had no effect on the situation.