[railroader]

For Jordan to fall would be the beginning of the end for Israel. Jordan is the most rational neighbor they have.

Actually, it would be the beginning of the end of ISIS. In the past, Israel has pledged (unsolicited) to defend Jordan from Syria invasion. So I believe an actual ISIS attack on that country would invite massive air strikes by the Israeli Air Force and possibly even ground forces to wipe out ISIS.

[Genoa]

Can you imagine a scenario in which the Sunni caliphate is at war with Iran and Israel at the same time? That would be beyond strange.

[cripplecreek]

The real problem for Jordan would come from inside the country.

[grania]

My head is spinning. Israel is pledged to defend Jordan, and I agree it's finally a fight they can't avoid. But the troops they'd be fighting are the ones who were fighting Assad, and Israel doesn't want Assad in power, do they? So will you have a weird situation where Israel, Assad, Iran, the sane part of Iraq, and even Turkey would have to put their hostilities on hold and defeat the US and Saudi proxies (ISIS) in Syria from destroying other countries?

Could an outcome of this be nobody will want US "help" anymore?