The only time I ever posted about 'the Madman Theory' was when I wrote a review of the 'Ellery Queen' novel (actually written by my beloved Jack Vance) The Madman Theory. The 'Madman Theory' was attributed to Richard Nixon by H. R. Haldeman:
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 angry—and he has his hand on the nuclear button" and Ho Chi Minh himself will be in Paris in two days begging for peace.
The basic gist is that an opponent would be reluctant to provoke a madman... Trump's decision to retaliate against Iran for shooting down a drone was immediately followed by a reversal, supposedly ten minutes before the planes were to have been sent to strike Iran. Trump claimed that his change of policy was motivated by compassion and a sense of proportionality, but cynical persons aver that his boss called him to tell him to back off. While Trump said the military was 'cocked and loaded', it seems that the Republican congresscreeps were cockblocked. Whether or not Trump is bluffing or actually had a change of heart regarding an actual attack on Iran, all I can really say is that I am thankful that my brother Vin retired from the Army in April.
The problem with the Madman Theory is that it doesn't work if the person using it is actually a madman.