Nixon didn't exactly end it overnight. He had thousands of tons of bombs to drop on neighbouring countries like Cambodia, first, killing untold thousands, before things wound down.
No, but if you look at troop levels, he began the drawdown in his first year. But his strategy was to make the North Vietnamese so scared of him that US troops could leave. Hence the bombing.
Of course he could not publicly take credit for this, because that would have interfered with the image he was trying to project to North Vietnam.
