The reason that you don't see Egypt massing its tanks and Jordan mobilizing its Army Reserves is the same...they are both pissed off at Al Qaeda bombing the hotels in Jordan and at Sharm al Sheikh.
Likewise, all of the regional players know as well as everyone else that the botched German prisoner swap of the PFLP terrorist in Europe for the captured German "tourist" in Iraq connected Al Qaeda to Hezbollah (because that's where the PFLP terrorist immediately fled when released - to Southern Lebanon's Hezbollah stronghold).
So Egypt and Jordan aren't going to go aid the people who bombed their big hotels; i.e. Hezbollah/Al Qaeda.
Nor do Iran and Syria appreciate the trickery that Al Qaeda/Hezbollah has been doing regarding dragging them into this war.
If Egypt was massing its armor and Jordan was mobilizing troops, it would be a different story.
But they aren't...and you can look to tangible actions (or inactions) like that to verify all that I have said above.
Is Egypt or Jordan mobilizing? Nope. Would Iran only fire 1 missile if they wanted to attack Israel? Nope.
Would Saudi Arabia blame Hezbollah if the kingdom was going to go to war with and for Hezbollah against Israel? Nope.
Would Iran just "forget" to warn Israel about attacking Hezbollah? No.