The Past as Prologue
There's a backstory behind the US assertion that American troops would have fought if they had been in the same position as British soldiers who were taken in a cross-border raid by Iranian forces. Time Magazine reports a firefight last year between a joint US-Iraqi patrol that surprised an Iranian force in Iraqi Kurdistan. Some details are apparently still secret. But here's Time's account for whatever it is worth.
U.S. soldiers from the 5th Squadron 73rd Cavalry 82nd Airborne were accompanying Iraqi forces on a routine joint patrol along the border with Iran, about 75 miles east of Baghdad, when they spotted two Iranian soldiers retreating from Iraqi territory back into Iran. A moment later, U.S. and Iraqi forces came upon a third Iranian soldier on the Iraqi side of the border, who stood his ground. As U.S. and Iraqi soldiers approached the Iranian officer and began speaking with him, a platoon of Iranian soldiers appeared and moved to surround the coalition patrol, taking up positions on high ground. At that point, according to the Army's statement, the Iranian captain told the U.S. and Iraqi soldiers that if they tried to leave they would be fired on. Fearing abduction by the Iranians, U.S. troops moved to go anyway, and fighting broke out. Army officials say the Iranian troops fired first with small arms and rocket-propelled grenades, and that U.S. troops fell further back into Iraqi territory, while four Iraqi army soldiers, one interpreter and one Iraqi border guard remained in the hands of the Iranians.
The official release says there were no casualties among the Americans, and makes no mention of any on the Iranian side. U.S. soldiers present at the firefight, however, tell TIME that American forces killed at least one Iranian soldier who had been aiming a rocket-propelled grenade at their convoy of Humvees.
The unstated implication of the account was that the US-Iraqi forces were acting as unprovocatively as possible while maintaining their self-protection. By legal right, if Americans have any of that any more, they could have called down fires on the Iranians intruding on Iraq once they had been threatened in that way. As it was, they apparently defeated the Iranian force with organic weapons, though one wonders what became of the Iraqis who were taken by the Iranians.
According to some points of view, the very aggressiveness of Iran is precisely the reason it should be "engaged" diplomatically. However, it is probably the case that if the Americans in the Time story had not actively defended themselves, they would be prisoners in Teheran right now and not all the diplomats in the UN would be able to get them out.