These sorts of cowardly acts are going to continue. They will continue because we are comparing apples to oranges. The followers of Isis do not value human life the same way normal people do they really don't care whether they live or die, it's very hard to combat that. Sorta like stopping kamikaze pilots in WWII. The only way you will stop Isis is wholesale eradication and that starts with containment. EVERY single Muslim male under the age of 45 is suspect, they need to be locked down. Flights in an out of Syria, and other areas with large Muslim populations need to be immediately stopped. The areas that are under Isis control need to be eradicated, depopulated. The problem is, this is inhumane and wont (and probably shouldn't) be supported by the US. Without doing this, we'll continue to see these sorts of cowardly attacks.