I think we have to look at real life for a possible answer. In Gulf War I, it seemed that Sadaam had some WMD of the chemical types, based on evidence from the Kurds. He also knew that if he used them against the US led coalition, we PROBABLY would have turned Bagdad and other places of note into fused glass....Sadamm KNEW that if he sent WMD against Israel....well, let's just say that our guys would not have had to bother picking up any pieces....there wouldn't be any pieces....
A buddy of mine was in GWI. He was with a MASH unit with 82nd Airborne. The unofficial word he heard was if they saw the Israeli Army approaching, they do three things:
1) Run Up a BIG American flag
2) sling longarms over shoulder
3) Wave and Point towards Bagdad
He also heard (You know how rumors are) that the night that Sadaam sent Scuds into Israel, our AWACS saw the ENTIRE Israeli airforce IN THE AIR. One guess where THEY were going. George Bush talked them down. Barely.