When a misunderstanding led to the United Nations threatening to wage war on Thor and Asgard, Iron Man was sent in by the United States to try and calm things down. The stubborn God of Thunder refused, leading Tony to don his Thorbuster armour which was powered by an Asgardian crystal (containing a sliver of Odin Force) given to him by Thor to try and find a renewable form of energy for the world. With powers equivalent to that of The Destroyer, Iron Man gave Thor a pummelling, but the battle ended in a standstill when Thor tore the armour from him and the Armoured Avenger was then forced to flee.
