Should we bomb Iran for plotting to blow up a Washington, D.C., restaurant in order to assassinate the Saudi ambassador?

Probably not.

Should Iran be worried that we might?

Absolutely.

And yet, within hours of the Justice Department charging elements within the Iranian government (the Quds Force of the Iranian Revolutionary Guard) of scheming to commit an act of war against us, the administration made it clear that it wanted a diplomatic response to the foiled scheme. A Pentagon spokesman explained: “The U.S. military has longstanding concerns about Iran’s malign influence in the region. But with respect to this case, it is a judicial and diplomatic issue.” Never mind that the “region” in this instance just happened to be two miles from the White House.

"The philosophical divide between mainstream hawks and mainstream doves is hardly absolute." -- Jonah Goldberg

White House spokesman Jay Carney quickly reassured everyone that the White House would focus “on working through economic measures, sanctions, as well as diplomatic measures to isolate Iran.”

By the time the president addressed the plot on Thursday, it came as no surprise when he said his administration’s first priority would be the criminal prosecution of the alleged perpetrator and then a lot more paper-pushing and talk.

Obama might be right that violence isn’t the answer. But why the rush to say so?

I think the explanation is more philosophical and psychological than tactical or strategic. It’s hardly controversial to say that the Obama administration prefers legalistic, multilateral, and diplomatic solutions to abiding problems rather than military ones.

A far more controversial claim is that Republican administrations, not to mention conservative hawks, prefer legal, multilateral, and diplomatic solutions to problems, too. But it also happens to be true. George W. Bush spent a lot of time at the U.N. before we invaded Iraq. He never resorted to military action against Iran or North Korea, despite the utter futility of diplomatic efforts and economic sanctions. Sure, the Right is probably more eager to use force, but it’s also more eager to seem like it will.

The philosophical divide between mainstream hawks and mainstream doves is hardly absolute. Obama ordered the bombing of Libya and the killing of Osama bin Laden. In his Nobel Peace Prize speech, Obama wisely, albeit awkwardly, conceded that the aphorism “violence never solved anything” is wrong. “To say that force is sometimes necessary is not a call to cynicism — it is a recognition of history, the imperfections of man, and the limits of reason.”

One might ask: What else does Iran have to do to demonstrate the diminishing returns of reasonableness? It’s been killing Americans in Iraq and Afghanistan. Obama’s own Treasury Department announced in July that Iran has formed a strategic partnership with al-Qaeda. It murdered its own citizens when they organized to demand democracy — precisely the sort of despotic behavior Obama says justified regime change in Libya. It’s the chief sponsor of terrorism in the Middle East, and it has exported terror all around the globe.

Again, I’m not arguing for dropping a bomb on the Quds’ headquarters, though I can’t say I’d mind it if we did. But I see nothing wrong with the Iranians thinking we might.

And that’s this administration’s problem: It has an obsession with the appearance of reasonableness.

It doesn’t fully appreciate that the threat of force is what encourages reasonableness in many quarters of the globe. Ronald Reagan was happy to negotiate with the Soviets, but he also kept them wondering if he might bomb before breakfast. Teddy Roosevelt spoke softly because he carried a big stick.

Just look at Israel’s problems these days. The White House signaled that it would pursue what amounted to a new policy of even-handedness between the Israelis and Palestinians. In ways large and small, it put slack in the bond between the U.S. and Israel.

What happened next? Turkey began demonizing Israel and saber-rattling in her direction. Palestinians opted to end-run the “peace process” and go straight to the U.N. for statehood. The junta ruling Egypt has played footsie with anti-Israel mobs.

North Korea hasn’t refrained from invading South Korea because it’s against the law, nor has China left Taiwan alone out of a passion for reasonableness.

In short, the fear that the U.S. will do what it takes to defend its national interests, allies, and ideals is what makes it possible to hash out our disagreements in swank European conference rooms. Lose the fear, lose the incentive for reasonableness.

Iran won’t even consider being reasonable until it’s afraid of us. And immediately ruling out anything but talk after every insult isn’t very scary.

Jonah Goldberg is a visiting fellow at AEI.