This is a rather scary thought,

"There is another path, of course. Simply put: if a US city is nuked, the US will have to nuke someone, or let it stand that the United States can lose a city without cost to the other side. Defining “the other side” would be difficult, of course – do you erase Tehran to punish the mullahs? Make a crater out of Riyahd? These are exactly the sort of decisions we never want to make. But let’s say it happens. Baltimore: fire and wind. Gone. That horrible day would clarify things once and for all. It’s one thing for someone in a distant city to cheer the fall of two skyscrapers: from a distance, it looks like a bloody nose. But erasing a city is a different matter.
Everyone will have to choose sides. That would be one possible beginning of the end of this war."

If were were nuked, I think the horror and anger and fear would be so great, we would undoubtedly do something horrible in return. Winning the war on terror is the only option, the only choice we have is how we win it. We fight this now to avoid the greater fight in the future. I still think it makes sense.