In light of the ignorant bellicosity that he's once again trumpeted in the face of the Georgia crisis (see here), I'd posit the following, if he becomes president:
--Over/under for the likely average number of wars we'll be engaged in at any given time during his presidency: 2.5.
--Likelihood of his using nuclear weapons: .3.
On the former, note that we're at 2 wars already (which he is reluctant to reduce to 1) and that he appears to want to fight Russia, China, Iran, and presumably Syria and North Korea.
On the latter, note that Cheney, his only Bush Administration near-twin for bellicosity (!!), reportedly pushed internally for the use of nuclear weapons against Iran. I wonder if the probability I offer is way too low.