June 20, 2014 | The Wall Street Journal

Book Review: ‘A Time to Attack’ By Matthew Kroenig

Here's a prediction: Next month in Vienna, Iran and the P5+1 world powers will extend the interim agreement they struck six months ago on Iran's nuclear program. Secretary of State John Kerry will hold a press conference, offering both sides solemn praise for finding common ground. All the while, through this tough compromise and historic collaboration, the Islamic Republic's 9,000 spinning centrifuges will keep on enriching uranium; the other 10,000 installed centrifuges won't be dismantled. Eventually these centrifuges, or thousands of new-and-improved ones, will be able to produce bomb-grade fuel.

Whether the official nuclear agreement is extended another six months or a year or more, the Iranian regime will not abandon its 30-year project. So the U.S. will face an unavoidable choice: accept a nuclear Iran or launch a pre-emptive military strike. Matthew Kroenig, a former Pentagon official who focused on the Iranian nuclear challenge under Defense Secretary Robert Gates, sees this reality clearly. His book, “A Time to Attack,” embraces the military option because he believes it is the only way to stop the clerical regime's nuclear drive.

Mr. Kroenig, a professor at Georgetown, is commendably straightforward in dispensing with the naïve hope that Iran's nuclear program is peaceful in nature: “Iran would like to build nuclear weapons. The only people Tehran is fooling at this point are people who want to be fooled.” He annihilates the argument that the Islamic Republic will go the way of Japan, maintaining a civilian nuclear program but never building a bomb. “It is simply implausible that Iran would go to such great lengths to get one screwdriver's turn away from the most powerful weapon on Earth—a weapon that would help Iran meet is foremost geopolitical goals—and then suddenly . . . voluntarily stop short,” he writes, noting that the regime has so far spent $100 billion on this bid.

President Barack Obama insists that he is ready to attack Iran to keep it from getting the bomb—in 2012, he called a nuclear Iran “unacceptable”—and Mr. Kroenig takes the president at his word. This may not be a credible position, given the president's record on Syria, but Mr. Kroenig argues that “no president would want to go down in history as the leader who let Iran acquire nuclear weapons on his watch, especially if nuclear weapons in Iran one day result in a devastating nuclear war.”

Like the president, the author would like to see the current nuclear negotiations succeed. But he's extremely doubtful they will. “Security, prestige, and domestic politics [are] the three most important reasons why countries decide to build nuclear weapons,” he writes, citing a Stanford University study of nuclear-armed states. “All three motivations are pushing Iran toward the bomb.” Mr. Kroenig doesn't discuss Iranian internal politics, but he should have. A recent volume of Ali Akbar Hashemi Rafsanjani's autobiography, for instance, has the former Iranian president bragging about the regime's nuclear gambit: “The Americans are really fooled,” the mullah wrote.

Mr. Kroenig helpfully emphasizes a key detail that often goes unmentioned in public discussion of centrifuges and plutonium-producing heavy-water reactors. “Iran is building ICBMs,” he writes. “No country on Earth, not even the United States, mounts conventional warheads on ICBMs. Traditionally, ICBMs have had one purpose: to deliver nuclear warheads thousands of miles away. If Iran is not developing nuclear weapons, then why does it have such a robust ICBM development program?”

Although not opposed to the use of sanctions as a diplomatic tool, Mr. Kroenig doesn't see them stopping Tehran's nuclear quest. Iran's economy has been devastated by sanctions, yet that hasn't halted atomic progress.

So if diplomacy and sanctions won't stop the mullahs, is there another strategy short of bombing that might? Mr. Kroenig is pessimistic. Iran is now much better prepared to deal with aggressive malware attacks, like the computer virus Stuxnet that briefly gummed up a lot centrifuges. Just about everyone in Washington dreams of regime change, even if they don't say so publicly. But that prospect offers little hope to Mr. Kroenig: The regime ruthlessly crushed the pro-democracy Green Movement in 2009.

Clandestine, plausibly deniable military operations also aren't a serious option, he argues. The assassination of Iranian nuclear scientists, presumably carried out by Israeli agents, hasn't accomplished much. And even if the U.S. or Israel could get special ops teams or stealthy aircraft in position to attack critical sites, bunker-busting 30,000-pound bombs would be required to destroy the uranium enrichment site at Fordow, which is buried deep in a mountain. Everyone knows that only one country has these weapons.

Containment, the strategy that much of Washington's foreign-policy establishment has embraced by default, doesn't make much sense either. As Mr. Kroenig puts it: “Why would anyone believe that we would fight a nuclear war with Iran if we didn't even have the stomach for a conventional war with a nonnuclear Iran?”

Logically and relentlessly, Mr. Kroenig moves to the conclusion that if the U.S. is serious about stopping Iran from getting a bomb, it will have to strike. Only four sites—Fordow, a second enrichment facility at Natanz, a uranium-conversion facility at Isfahan, and a heavy-water reactor at Arak—need to be destroyed to set the program back decades, if not longer. Mr. Kroenig readily admits that there will be costs for preventive military action. Tehran will likely respond with terrorism, directly or through proxies. But Mr. Kroenig contends that those costs are much lower than allowing Iran to go nuclear. Whether or not he's right, we will soon find out.

Mr. Gerecht is a senior fellow at the Foundation for Defense of Democracies.