I don't dispute that he's saying "vote for Kerry at your own peril," I disagree with what the peril was.
Part of the problem is the questionable transcription of this quote, putting a period before "And then", as if the terrorist attack risk and the pre-9/11 risk were unique ideas. The way he said it, it was one long, awkward sentence, but it clearly led to that last point.
Anyway, he's absolutely right about Kerry reverting to a pre-9/11 mindset, he's said as much, and has been wishy-washy on whether or not we're actually in a war.