Nearly two decades ago, Israel started alerting the world about Iran's nuclear program. But the world ignored our warnings, wasting 10 years until the secret nuclear enrichment plant at Natanz was exposed in 2002. Then eight more invaluable years were lost before much of the international community imposed serious sanctions on Iran.
Throughout that time, the ayatollahs systematically lied about their nuclear operations, installing more than 10,000 centrifuges, a significant number of them in a once-secret underground facility at Qom. Iran has blocked International Atomic Energy Agency (IAEA) inspectors from visiting its nuclear sites, refused to answer questions about the military aspects of its program, and rejected all confidence-building measures. Iran has tested long-range missiles capable of reaching any city in the Middle East and, in the future, beyond.
Iran is also the world's leading state sponsor of terror. It has supplied more than 70,000 rockets to terrorist organizations deployed on Israel's borders and has tried to murder civilians across five continents and 25 countries, including in the United States. In July, Iranian-backed Hezbollah terrorists killed five Israeli tourists, among them a pregnant woman, in Bulgaria. Iran's forces have attacked American troops in Afghanistan and Iraq. Its agents are operating in Yemen, Africa and South America. By providing fighters and funds, Iran is enabling Syrian dictator Bashar al-Assad to massacre his own people.
Iran has done all this without nuclear weapons. With them, it can commit incalculable atrocities anywhere in the world, beginning with Israel. As the chief of staff of the Iranian military recently stated, "the Iranian nation stands for the full annihilation of Israel." Last week, Iranian President Mahmoud Ahmadinejad said "the annihilation of the Zionist regime is the key for solving the world problems."
Accordingly, Israel believes that Iran is far from forfeiting its nuclear ambitions. Our conviction is based on Iran's record of subterfuge and terror together with its genocidal rhetoric. It also reflects the inability of the permanent members of the U.N. Security Council and Germany (the "P5+1") to negotiate a compromise with Iran.
In their first round of talks with Iranian officials, late in 2009, the P5+1 demanded the suspension of all enrichment activities in Iran and the transfer of its stockpiles, then enriched to 3.5%, abroad. Iran rejected those conditions and escalated its enrichment process to 20%, which can be enhanced to weapons-grade in a matter of weeks.
Iran now has amassed roughly 225 pounds of 20% uranium and 11,000 pounds of 3.5%, sufficient for almost five nuclear bombs. Rather than stand by its initial demands, however, the P5+1 is now seeking merely the cessation of Iran's 20% enrichment, the removal of its 20% stockpile, and the closure of the facility at Qom. Arguably, this would be the first stage in the phasing out of Iran's nuclear program. But Iran has rejected even this preliminary gesture.
Iran will continue to drag out the negotiations while installing more centrifuges. These, according to the IAEA, are spinning even faster. The sanctions, which have dealt a blow to Iran's economy, have not affected the nuclear program. Meanwhile, more of Iran's expanding stockpile will be hidden in fortified bunkers beyond Israel's reach.
No country has a greater stake than Israel in using negotiations and economic pressure to dissuade Iran from developing nuclear weapons. We appreciate the determination of President Obama and the U.S. Congress to advance the sanctions and their pledge to keep all options on the table.
At the same time, the president has affirmed Israel's right "to defend itself, by itself, against any threat," and "to make its own decision about what is required to meet its security needs." Historically, Israel has exercised that right only after exhausting all reasonable diplomatic means. But as the repeated attempts to negotiate with Iran have demonstrated, neither diplomacy nor sanctions has removed the threat.
A combination of truly crippling sanctions and a credible military threat—a threat that the ayatollahs still do not believe today—may yet convince Iran to relinquish its nuclear dreams. But time is dwindling and, with each passing day, the lives of eight million Israelis grow increasingly imperiled. The window that opened 20 years ago is now almost shut.
Mr. Oren is Israel's ambassador to the United States.