I'm not sure if Israel wants this war contained. And from the public statements of our Administration, I don't think they want it contained either. It would seem we must be ready for war with Iran and Syria.
As for Iran, they're going to rage and roar but they're going to have a difficult time moving men and materiel into the war zone. That's also one thing we accomplished in Iraq. That, in essence, is containing the war. Of course, if Iran does decide to attempt to move conventional forces toward Syria, that's a long, lonely, and exposed road and we own the air. I suspect they'll move some Revolutionary Guard covertly, too little and too late. Could be wrong - we'll see.
They don't. This is a critical first step before putting the smack down on Iran. It's now or never.