In The Twilight War, government historian David Crist outlines the secret history of America's 30-year conflict with Iran. The book, based on interviews with hundreds of officials as well as classified military archives, details how the covert war has spanned five American presidential terms and repeatedly threatened to bring the two nations into open warfare.
Crist tells Fresh Air's Terry Gross that there have been several incidents that have almost resulted in battle over the past 30 years.
Crist himself observed a close call between American and Iranian vessels in 2003, when he was a member of the special operations forces.
"We were about an hour into the mission when all of a sudden, three Iranian Revolutionary Guard boats come streaming across from the other side of the river, stop just in front of us, unmask their guns and point them straight at us and then proceeded to bombard us with a hail of choice American obscenities," he says. "Our commander at the time was a Navy Seal who had lived in Tehran until he was 16 and he tried to talk with them. He even rigged an Italian flag turned sideways - which looked liked an Iranian flag - to show we had no hostile intent. We unmasked our guns, we called for our airpower and I thought we were on the absolute brink of a major shooting war with Iran."
Crist and his fellow troops were ordered to withdraw and not antagonize the Iranians by high-level military officials.
"So we pulled back with the Iranians trailing us, and what I didn't realize at the time was that that was a pretty significant mistake," he says. "By doing so, we surrendered that entire waterway to the Iranians and they were in the process of the counter-invasion of Iraq. And they were flooding southern Iraq with forces [and arming the Shiite militias]. And what these three boats were doing was trying to prevent us from interfering with that counter-invasion."
Crist says the U.S. should have stopped the Iranians - or made a more concerted effort to stop the Iranians.
"By backing down, we acquiesced to them," he says. "And it goes far beyond this one boat incident. ... We missed an opportunity, I think, for reducing the amount of influence Iran was going to have in Iraq afterwards."