Aside from the senseless loss of life on both sides and the tremendous waste of money it will be, there are still three terrible things about a U.S. attack on Iran that have not been mentioned:
1. The U.S. president on his own accord can order American troops to attack without consulting Congress—just like Truman and Korea. No man—Republican or Democrat, liberal or conservative—should have that kind of power. Yes, I know what the Constitution says—I have read and studied it many times and taught it—but it doesn't matter what the Constitution says. Just ask the Republicans—they have been violating it left and right since they gained control of the Congress under Clinton. The Founders never envisioned the president to have this kind of power. It is dangerous, and not just in the hands of Obama. See Lew Rockwell's "Down with the Presidency."
2. The overwhelming majority of U.S. troops will "give a snappy salute" and do what they are told, including kill Persians by the thousands, if Obama gives the order. Whether such an attack is just is a thought that will not even enter their mind.
3. Americans will cheer for the troops and call them heroes. Those who criticize the troops for fighting yet another unjust war (like me) will be called unpatriotic. They will be told to only condemn Obama and the politicians, never the troops. It's not their fault.