After spending a week traveling the frontline of the “war on terrorism” — from the aircraft carrier U.S.S. Ronald Reagan in the seas off Iran, to northern Iraq, to Afghanistan and into northwest Pakistan — I can comfortably report the following: The bad guys are losing.

Yes, the dominos you see falling in the Muslim world today are the extremist Islamist groups and governments. They have failed to persuade people by either their arguments or their performances in power that their puritanical versions of Islam are the answer. Having lost the argument, though, the radicals still hang on thanks to gun barrels and oil barrels — and they can for a while.

Because, while the radicals have failed miserably, our allies — the...