The 20th century was a time of great and terrible revolutions. The Russian Revolution of 1917 promised a communist utopia. It delivered man-made famines, the Gulag Archipelago and at least 20 million murdered. The Chinese Revolution of 1949 brought the Great Leap Forward and the Great Proletarian Cultural Revolution; estimates put the death toll as high as 65 million.

Thirty years ago, on February 1, 1979, the Ayatollah Ruhollah Khomeini led the Iranian Revolution. Like the Russian and Chinese Revolutions, it promised a global conflict leading to a new era of justice. But unlike those earlier revolutions, it would be not the proletariat bringing down the capitalists, but the Muslims rising up against the "infidels" - their power, values, laws, and their satanically seductive way of life.

I was in Iran 30 years ago -- a young foreign correspondent lucky enough to be sent to cover a historic upheaval. I recall standing in a dense crowd in the dusty streets of the holy city of Qom as Khomeini appeared on the roof of a modest bungalow, wearing black robes and turban. He did not smile like a politician would. His face was stern, like a father gazing on an errant son. He slowly raised his hand. The crowd erupted in frenzy. "There have been only a few such figures in history," an Iranian instructed me. "Moses, Jesus, Mohammad - and now there is Khomeini."

Many of my journalistic colleagues cast the revolution in a favorable light. The Shah, they said, had been a despot; Khomeini expressed the will of the people; the hatred of America was Washington's fault. Soon, alcohol would be banned and women would be forced to cover themselves from head to toe in black chadors. Most foreign correspondents would move on to other countries, other stories.

Many Iranians who were not Islamists supported the Iranian Revolution nevertheless. They believed Khomeini would show tolerance and embrace diversity. But he declared disobedience to his government a "revolt against God." A few years later, many of those I had known in Iran were dead or in prison or in exile abroad.

Today, the 30-year-old Iranian Revolution appears simultaneously dangerous and decrepit. Iran has made Syria its client, created Hezbollah as its proxy, and adopted Hamas. A new report from the International Institute for Strategic Studies says Iran is likely to produce enough low-enriched uranium to make a nuclear bomb before the end of this year. Long-range ballistic missiles are under development as well.

But, at the same time, Iran's attempt to export its revolution to Iraq has failed for now. When Israel retaliated against Hamas for years of missile attacks, Iran's support was only rhetorical. Iran's economy has been crumbling and falling oil prices have hit Iran hard in recent months. Further, while Iran has spent a fortune on its nuclear programs, it has built few oil refineries. So, despite being one of the world's major oil producers, Iran must import much of its gasoline.

Research by the Foundation for Defense of Democracies (the think tank I head), led by FDD senior fellow Orde Kittrie, a former State Department official, reveals that Iran gets most of its imported fuel from just a few companies - Vitol, Trafigura, British Petroleum, and Total -- all of which have financial interests in the U.S.

That presents an opportunity: President Obama could pressure these gasoline suppliers to turn off the flow. Indeed, recent Congressional action reportedly persuaded the Indian company, Reliance, to end gasoline sales to Iran.

Obama could make clear to average Iranians that their rulers are to blame - they are the ones isolating and impoverishing them. And for what? So they can wave a big gun on the world stage? So they can attempt genocide and provoke a nuclear exchange with Israel? There is every reason to believe most Iranians don't want that.

President Obama has said that the world "cannot allow Iran to get a nuclear weapon. .... And I will do everything that's required to prevent it." He also has said: "If we can prevent [Iran's rulers] from importing the gasoline that they need, that starts changing their cost-benefit analysis. That starts putting the squeeze on them."

Exactly. The Iranian Revolution is 30 years old. The new administration still has time to limit its final death toll.