Why the Pentagon Thinks Attacking Iran is a Bad Idea

Iranian soldiers on parade for President Ahmadinejad.

Most believe that the U.S. military could, with some effort, quickly reopen the strait and most likely sustain little damage at the hands of the 1970s-era planes and weapons that make up the bulk of the Iranian Air Force. But the greater concern is the asymmetric chaos that Iran could unleash in neighboring countries, says Larry Wilkerson, who was chief of staff to Secretary of State Colin Powell. Wilkerson recalls that in his first briefing after taking that job in 2002, the topic was the attacks Iranian-backed Hezbollah could mount against Israel and elsewhere. "They said Hezbollah is the A-team, and not someone we want to take on, because they were essentially 10 or 15 times the capability of al Qaeda," says Wilkerson.

U.S. troops in Iraq likely would face stepped-up attacks by Iranian-backed militias, and the Karzai government in Afghanistan would collapse, says Riedel. "He couldn't choose between us and the Iranians." A U.S. strike, analysts warn, could also have the undesired effect of bolstering Ahmadinejad—as a nation under attack rallies around even an unpopular leader—and alienating the more progressive, anti-Ahmadinejad factions.

An Israeli strike on Iran—with or without U.S. support—would offer all of these risks and more minuses, say senior defense officials. For this reason, in recent meetings in Israel, Mullen "conveyed his less-than-enthusiastic view of an Israeli attack," says a senior military official. Says Riedel, "From an Iranian perspective, Israel would be flying American-made F-15s and F-16s, dropping bombs made in the USA," he adds. "Within the Pentagon, not only do they see the downsides, they tend to think that if someone's going to do this, they don't want to see it outsourced to another air force."

Still, it is in the best interest of the Bush administration to show that it takes Iran's threat to Israel seriously "in hopes of being able to restrain the Israelis," says Bacevich. The decision by scandal-damaged Israeli Prime Minister Ehud Olmert to step down once his party chooses a successor in September creates a new uncertainty. "I don't know whether that keeps an operation from happening. Olmert may want to do this one thing on his way out," says Riedel. "I, for one, am convinced that it's a very real possibility."

That possibility increases each time diplomacy falters. But the Pentagon's diplomatic war game concluded that talking doesn't guarantee resolution, either. There were some useful findings—the benefits of engaging Middle East neighbors, for example. "Regionally, there was very strong interest in limiting Iran's growth and power that we haven't exploited as a country," says the defense analyst.

Yet, just as in real life, direct talks with Iran proved consistently tricky in that exercise. "We could get small concessions and promises to talk again," the analyst adds. "But there were no significant breakthroughs or eurekas that made us say, 'This idea is so wonderful that we need to run down the hall and try it right now.' "

If diplomacy doesn't work, and the military route appears too problem-atic, there is a third possibility: a nuclear-armed Iran. Learning to live with that could be the next challenge Pentagon war gamers—and war planners—will have to face.