Sounds like some Iranian generals don't want to live long.
They see what is happening in Najaf as a weakness.
No, they saw what we did in Iraq - the Iraqi Air Force was a no-show, the Iraqi armor was easy destroyed and the Iraqi army either ran or was killed in place by our forces - all with absolutely minimal losses to us.
The Iranian generals' best chance might be to strike us by going into Iraq while our ground forces are still stretched thin and busy fighting the terrorists there.
Although I am sure our air forces (F-15 Strike Eagles, F-16s, A10 Warthogs, Apache attack helicopters, etc.) and armored forces (M1A1 Abrams tanks and Bradley Armored Fighting Vehicles with TOW missles, etc.) would be sure they go quite a warm welcome once they crossed the border into Iraq...
I'm reminded of Saddam's "Mother Of All Battles" ranting.