There is still much to learn about the Iranian-directed plot to blow up the Saudi ambassador in a Washington, D.C., restaurant. But if the Justice Department's information is correct, the conspiracy confirms a lethal fact about Iran's regime: It is becoming more dangerous, not less, as it ages.
Since the 1989 death of Iran's revolutionary leader, Ayatollah Ruhollah Khomeini, Western observers have hunted for signs of the end of the revolution's implacable hostility toward the United States. Signs have been abundant outside the ruling elite: Virtually the entire lay and much of the clerical intellectual class have damned theocracy as illegitimate, and college-educated youth (Iran has the best-educated public of any big Middle Eastern state) overwhelmingly threw themselves into the pro-democracy Green Movement that shook the regime in the summer of 2009.
But at the regime's apex—Supreme Leader Ali Khamenei, his praetorian Revolutionary Guard Corps, and the clergy who've remained committed to theocracy—religious ideology and anti-Americanism have intensified.
The planned assassination in Washington was a bold act: The Islamic Republic's terrorism has struck all over the globe, and repeatedly in Europe, but it has spared the U.S. homeland because even under Khomeini Iran feared outraged American power.
Iran truck-bombed the U.S. Embassy and Marine barracks in Lebanon during Reagan's presidency, calculating correctly that the Lebanese operational cover deployed in that attack would be sufficient to confuse U.S. retaliation. But the accidental shoot-down of Iran-Air flight 655 in July 1988 by the USS Vincennes unquestionably contributed to Tehran's determination that the White House had allied itself with Saddam Hussein and therefore the Iran-Iraq war was lost. The perception of American power proved decisive.
One of the unintended benefits of America being at the center of Iran's conspiracies is that the U.S. is often depicted as devilishly powerful. Running against that fear, however, is another theme of the revolution: America's inability to stop faithful Iranians from liberating their homeland—the entire Muslim world—from Western hegemony and cultural debasement. American strength versus American weakness is a dangerous dance that plays out in the Islamist mind.
Within Iran, this interplay has led to cycles of terrorism of varying directness against the U.S. Khamenei, who many analysts have depicted as a cautious man in foreign affairs, has been a party—probably the decisive party—to every single terrorist operation Iran has conducted overseas since Khomeini's death.
The once-humble, unremarkable Khamenei—who was given the office of supreme leader in 1989 by the once-great Don Corleone of clerical politics, Ali Akbar Hashemi Rafsanjani (who assumed Iran's presidency that same year)—has become the undisputed ruler of Iran.
It was Khamenei who massively increased the military and economic power of the Revolutionary Guards Corps while often playing musical chairs with its leadership. The supreme leader has turned a fairly consensual theocracy into an autocracy where all fear the Guards and the Intelligence Ministry, which is also now under the supreme leader's control. He has squashed Rafsanjani, his vastly more intelligent, erstwhile ally. He has brutalized the pro-democracy Green Movement into quiescence. And he has so far outplayed his independent and stubborn president, Mahmoud Ahmadinejad, whose populist-nationalist-Islamist pretensions annoy the supreme leader and outrage many religious conservatives.
Khamenei's growing power and sense of mission have manifested themselves abroad. He has unleashed the Guards Corps against the U.S. and its allies in Iraq and Afghanistan. As the Treasury Department recently revealed, Tehran has ongoing ties to al Qaeda. These date back at least a decade, as the 9/11 Commission Report depicted Iranian complicity in the safe travel of al Qaeda operatives and chronicled al Qaeda contact with the Lebanese Hezbollah and Tehran's éminence grise to Arab Islamic radicals, the late Imad Mughniyeh.
Many in Washington and Europe would like to believe that the assassination plot in Washington came from a "faction" within the Iranian government—that is, that Khamenei didn't order the killing and Washington should therefore be cautious in its response. But neither this analysis nor the policy recommendation is compelling.
Lord help Qasim Soleimani—the man who likely has control over the Revolutionary Guards' elite dark-arts Qods Force, which apparently orchestrated this assassination scheme—if he didn't clear the operation with Khamenei. He will lose his job and perhaps his life. For 20 years, Khamenei has been constructing a political system that is now more submissive to him than revolutionary Iran was to Khomeini.
And for 20 years the U.S. has sent mixed messages to the supreme leader. Under both Democratic and Republican presidents, the U.S. has tried to reach out to Iran, to engage it in dialogue that would lead away from confrontation. For Khamenei such attempts at engagement have been poisonous, feeding his profound fear of a Western cultural invasion and the destruction of Islamic values.
This deeply offensive message of peace has alternated with American-led wars against Iraq and Afghanistan. These wars spooked Tehran, radiating American strength for a time, but such visions ebbed.
Khamenei probably approved a strike in Washington because he no longer fears American military might. Iran's advancing nuclear-weapons program has undoubtedly fortified his spine, as American presidents have called it "unacceptable" yet done nothing about it. And neither George W. Bush nor Barack Obama retaliated against Iran's murderous missions in Iraq and Afghanistan.
President Obama has clearly shown he wants no part—or any Israeli part—in a preventive military strike against Iran's nuclear sites. And Mr. Obama has pulled almost all U.S. troops out of Iraq and clearly wants to do the same in Afghanistan. Many Americans may view that as a blessing, but it is also clearly a sign that Washington no longer has the desire to maintain hegemony in the Middle East.
That's an invitation to someone like Khamenei to push further, to attack both America and Iran's most detested Middle Eastern rival, the virulently anti-Shiite Saudi Arabia. In the Islamic Republic's conspiracy-laden world, the Saudis are part of the anti-Iranian American Arab realm, which is currently trying to down Iran's close ally, Bashar al-Assad's Syria, and squash the Shiites of Bahrain. Blowing up the Saudi ambassador in Washington would be an appealing counterstroke against the two foreign forces that Khamenei detests most.
The Obama administration will be tempted to respond against Iran with further unilateral and multilateral sanctions. More sanctions aren't a bad idea—targeted sanctions against the Revolutionary Guards and the sale of gasoline made from Iranian crude can hurt Tehran financially. But they will not scare it. The White House needs to respond militarily to this outrage. If we don't, we are asking for it.
In the 1980s and '90s, the U.S. failed to take Secretary of State George Shultz's wise counsel after Khomeini's minions bombed us in Lebanon. We didn't make terrorism a casus belli, instead treating it as a crime, only lobbing a few missiles at Afghan rock huts and a Sudanese pharmaceutical plant. But we should treat it as a casus belli. The price we will pay now will surely be less than the price we will pay later.
Mr. Gerecht, a former Central Intelligence Agency officer, is a senior fellow at the Foundation for Defense of Democracies.