Until someone is actually called upon to respond in a crisis, there’s really no way to know what they will do… and that applies to John McCain every bit as much as it does Hillary Clinton or Barack Obama.
It’s always, to one degree or another, a bit of a crapshoot.
The Foreign Policy Crapshoot
I agree. Nothing can fully prepare an individual for the presidency. Experience isn’t the be all, end all. A combination of factors including experience, judgment, and surrounding one’s self with the right people seem to be the ticket, but those factors are difficult to judge in advance.