Upvote:15
Well, by Nixon's own standard, his implementation of it certainly wasn't very effective. As quoted by his chief of staff:
I call it the Madman Theory, Bob. I want the North Vietnamese to believe I've reached the point where I might do anything to stop the war. We'll just slip the word to them that, "for God's sake, you know Nixon is obsessed about communism. We can't restrain him when he's angryβand he has his hand on the nuclear button" and Ho Chi Minh himself will be in Paris in two days begging for peace.
This was in 1969 or earlier (as Ho died that year). There were ongoing negotiations (yes, in Paris) since before Nixon took office, but the general North Vietnamese tactic was always to keep talking and keep fighting. After Nixon took office, The talks were completely deadlocked for the next 3 years. When the deadlock was broken in 1972, the agreement reached was for a cease-fire, followed by a US (but not North Vietnamese) withdrawl. Given how much longer that agreement took, and how the North seems to have very much gotten the better side of the deal, I think its quite fair to say that no "begging for peace", or in fact anything close to it, happened as a result of Nixon's policy behavior.