The broad debate on Iran can be divided into two common eras: before and after the release of the Iraq Study Group report. The report has re-energized the debate about engaging Tehran, but U.S. diplomacy with Iran should be seen only in part through an Iraqi prism. America's broad regional interests are also at stake with Iran.

Iran does not wield the wand to halt the sectarian strife that is destroying Iraq-an ability ascribed to it by some favoring engagement and, conversely, some advocating brinkmanship. And contrary to popular opinion, Iran has less influence in Afghanistan, since Tehran supported Ahmad Shah Massoud who treated the Shi‘a brutally. What Iran can do is to restrain the violence in Iraq to some degree, and prevent it from spreading to Lebanon, Bahrain, eastern Saudi Arabia and to the small sheikdoms in the Persian Gulf. And there is another reason for engaging Iran. Following other options to their logical conclusion yields the same conceivable result: a disastrous outcome for U.S. interests.

Rhetorical Bombs

The Iraq Study Group report has advocated dialogue with Iran (and Syria) as an integral component of a new Iraq strategy, with little time to lose. Given the U.S. preoccupation with Iran's nuclear power program, the ISG's recommendation of decoupling dialogue from any preconditions is especially positive. There is no hard evidence indicating Iran intends to develop nuclear warheads, and even if it did have such intentions, the indications are that Iran is years away from developing a bomb. Yet the Bush Administration continues to insist on a suspension of Iran's nuclear enrichment before any dialogue can take place. The U.S. approach has not only hardened the regime in Tehran, it has also inspired the vast majority of Iranians to defend what they see as their right as an independent nation.

Whether Iran has had its heart set on enriching uranium to weapons grade, I don't know. What remains clear is that Iran feels insecure after the U.S.-led support of Saddam Hussein during the Iran-Iraq War, the U.S. occupation of Iraq and Afghanistan and U.S. bases surrounding it on all sides. Also, the Bush Administration's negative rhetoric continues to fan Tehran's anxiety.

As advocated by the ISG, the U.S. has little choice but to start a dialogue with Iran with no preconditions. Engagement with Iran, along with other policy changes, could help the U.S. to gradually salvage its lost influence in the Middle East, save U.S. lives and treasure and avoid a wider conflict that could threaten the entire region and the world. Iran, because of its willingness to stand up to Washington on some issues, has acquired credibility in the region and is uniquely suited to help the United States improve its image in the wider Muslim world. Rapprochement with Iran and a more peaceful Iraq would allow the U.S. to maintain its presence in some Persian Gulf countries, but if the United States is forced out of Iraq, it may be forced out of all other Persian Gulf countries. Because the United States is closely identified with autocratic Arab rulers in the Persian Gulf, a forced U.S. withdrawal from Iraq could start a popular domino effect, forcing the United States to leave from every country in the Persian Gulf.

Options Toward Iran

What are U.S. policy options toward Iran? The U.S. could: bomb and invade Iran in an attempt to make Tehran malleable and stymie its nuclear program; attempt to push through UN sanctions or re-enforce unilateral sanctions with sanctions from a coalition-of-the-willing; ignore Iran and continue on its current course in Iraq and in the broader Middle East; or engage Iran in a dialogue, with no preconditions.

The first option would, in my opinion, result in a regional war that would be unpredictable and uncontrollable. And while Bush has cited oil prices as a reason for staying the war's course in Iraq, bombing Iran would cause oil to become scarce, sending prices sky-high. The world economy would grind to a halt. Iranians and Muslims worldwide would become anti-American as never before, with the U.S. forced to leave the Persian Gulf.

The adoption of effective and comprehensive sanctions by the UN seems doubtful because Russia, China, or both, are unlikely to agree. Even if the United States were to put together a coalition, Russia and especially China could supply much of Iran's import needs. Most importantly, sanctions are porous and would require a naval blockade of Iran to be effective. This would be seen in Tehran as an act of war and could lead to a conflict between the U.S. and China and Russia. Iran could retaliate by not exporting oil because it has enough foreign exchange to last a year. Iran could sabotage oil exports of Arab countries. Most importantly, sanctions will not work because the Iranians themselves support the government's quest for nuclear power and research.

Dimensions of Diplomacy

Staying the course and ignoring Iran could be an option if Iraq were not deteriorating rapidly and if Lebanon and the Palestinian territories were calm. The danger with this course is that it has already failed and there is no reason to believe that it will be more successful in the future. Again, the end result may be a forced U.S. withdrawal from the entire Persian Gulf.

The last option is the only practical one. Iran is unlikely to accept preconditions to talks and the United States loses nothing by engaging Iran. And Washington does have some inducements (or could play a key role in securing them) that Iran would be interested in: security guarantees from the United States and from the other permanent members of the UN Security Council; a timeline for total U.S. withdrawal from Iraq; as a bargaining ploy, withdrawal from the Persian Gulf (more on this below); removal of U.S. sanctions; assistance from the International Atomic Energy Agency for peaceful nuclear-power development; a timely resolution of Iran's foreign-military-sales claims against the United States, involving military equipment paid for under the Shah but never delivered by the United States because of sanctions, which Tehran is currently pursuing at The Hague; eventual restoration of full diplomatic relations with the United States.

And Washington is interested in receiving the following from Tehran: active support in reining in the Shi‘a militias in Iraq; pressure on Shi‘a factions in Iraq in cobbling together a government of national reconciliation; support for an Arab-Israeli peace agreement and, upon reaching such an agreement, diplomatic relations with Israel; cooperation in Afghanistan and in the fight against terrorism; termination of support for Hizballah and Hamas; termination of Iran's nuclear enrichment and heavy water reactor programs.

If Iran agrees to the most intrusive inspections of any country, such an agreement could serve as a model to be applied to all countries in the future. Iran would likely also agree to reduce its support for Hizballah and Hamas if this is tied to a peace settlement between the Palestinians and Israel. The United States would probably agree to a timetable for its withdrawal from Iraq, but would not agree to a broader withdrawal from the Persian Gulf-which would in all likelihood be acceptable to Iran.

Negotiations will be painful and difficult as the two sides neither understand nor trust each other. But negotiations have historically been successfully concluded with similar levels of distrust. And lastly, there is no viable alternative for the United States. There is little time to waste given the rapidly deteriorating position on the ground in Iraq and in Lebanon and the Palestinian territories. Further, the United States must preempt a widespread anti-U.S. backlash that could force a total withdrawal from the region.

Hossein Askari is Iran Professor of International Business and International Affairs at the George Washington University.