They know that any such event that can be tied to Iran, would be an act of war, against which Bush could respond with the full force of the US military without any need for advance congressional permission
But what is listed is their plan is their intent to attack U.S. Embassies which are legally U.S. territory located in a foreign nation. Therefore, an attack on the sovereign territory of The United States.
"Notably absent on the list is any mention of an attack on US soil."
check again:
"casualties by exploding germ and chemical bombs as well as dirty nuclear bombs across western and Arab cities."