The question was asked..
I can only offer that we should not (1) do "exactly" what the terrorists wanted (as bush2 did), and (2) do not attack a country that had nothing to do with said terrorism (Dry drunk; Bush2 again).
Religious terrorism had been going on for thousands of years with no solution as of yet (holy wars, pogroms, inquisition, now many feel todays war is a war against Islam). And before this, when Christians were a minority, they were fed to the lions.
I believe the answer is outlined in John Lennon's song "Imagine" (nothing to kill or die for).. Education may be the key, because educated people tend to leave ancient superstitions behind. Religion makes it possible for charasmatic leaders get groups together willing to kill. But even if there were no religion, we would get power mad psychopaths (they always seem very driven to climb into positions of power)..
I believe the combination of education and economic justice (liberal ideas) would be the most effective methods we could nurture to promote world peace. War mongering as CON's are doiong in our name, only causes hate to fester, ensuring generations for more bloodshed.