Saddam doesn't need to threaten Israel with ground troops to get them involved. Sending over a few Scuds loading with chemical, biological or nuclear material would fit the bill just fine. The trouble is, for Saddam, that he won't like the Israeli reaction much. If there was anything left of Iraq to bomb after the Israelis are through, our bombers from Diego Garcia would have beacons that they could probably see near the mouth of the Persian Gulf.
My worry is that Saddam knows full well that the jig is up for him unless he gets allies and strikes first. He and the other major terrorist nations in the area (Syria and Iran) could probably coordinate an attack on Israel and on various oil fields in the Persian Gulf, just to really screw things up. By the way, does anyone know if either Iran or Iraq have missiles that can reach Diego Garcia?
How's this for an alternative nightmare scenario? Through its puppet Shi'ite rebel groups in the south, Iran launches its own pre-emptive coup against Sadaam, removes him and replaces him in Baghdad with an "Islamic Republican" regime, before the preparations for our own attack are complete. All very democratic of course, just the way it is in Iran. Would we then have to re-think our whole strategy, while the Iranians tighten their grip on Mesopotamia?