Proof?
I dimly remember hearing of an attempt, or a plot, or whatever it was, on George Bush when he was visiting Kuwait in 1992 (I guess). I don't remember the details, I was only 13 at the time. I haven't heard anything about it since. I've tried googling it, but haven't found anything. It's not mentioned in Bush's Wikipedia biography. It's not on a list of serious assassination attempts against US presidents on Wikipedia (there're 13 entries, not counting the successful attempts). It wasn't mentioned in the buildup to the war by anti-Saddamies. Even though it would make a good argument for how dangerous this guy is.
Which brings me to part 2: Where's the difference, in the "goner" stakes, between a successful and a failed attempt at the life of a US President? (Note that the letters US are important here. Nobody supported a Libyan invasion of the US after Reagan ordered several assassination attempts of Ghaddafi, one of which killed Ghaddafi's 4 year old daughter. Just an aside observation, and not really my point.)
In fact Clinton launched several cruise missiles to Iraq as counterblow for Saddam's plant.