As U.S. forces encircle Najaf to "capture or kill" Moqtada Sadr and disband his militia, the Mahdi Army, it is important that policymakers consider the costs of such an operation. Reining in Sadr and his militia is important to U.S. objectives, but it may prove to be a Pyrrhic victory. Grand Ayatollah Ali Sistani has refused to sanction the entry of U.S. forces into Najaf, and he has publicly warned the United States about crossing a "red line" that will inflame Shiite public opinion, not only in Iraq but from Pakistan to Lebanon. The fallout is likely to make U.S. objectives in Iraq and its surrounding region more difficult to realize. It will instead cause instability, violence and anti-Americanism in quarters where such tendencies have so far not been evident.

U.S. policymakers will do well to consider the aftermath of the Indian Army's sack of the Sikh holy shrine, the Golden Temple, in Amritsar in 1984. The government of then-Prime Minister Indira Gandhi was facing a serious law-and-order situation in the province of Punjab. The trouble was caused by Sikh terrorism, led by Jarnail Singh Bhindranwale and his followers who were lodged inside that shrine. Gandhi decided to end the problem by ordering the Indian army to sack the Golden Temple. The terrorists were killed in heavy fighting, but the real casualty was India's stability. Sikh soldiers and units across India reacted to the operation by revolting, and two of Gandhi's trusted Sikh bodyguards took revenge later by killing her. Her murder in turn led to the killing of thousands of Sikhs in New Delhi and other cities in northern India, deeply scarring the country. Gandhi had a strong case for entering the Golden Temple to end Sikh terrorism, many of whose victims were Sikhs. However, the reaction of all Sikhs to the violation of the sanctity of their shrine was uniformly one of horror and anger.

Violating the sanctity of Najaf can similarly inflame Shiite opinion across the Middle East and change the tenor of Shiite politics. It can harden Shiite attitudes toward U.S. occupation and in the process weaken the position of those Shiites who are engaged with the United States. Most notably, it will constrict Ayatollah Sistani in managing Shiite politics. Much has gone wrong for the United States since the fall of Baghdad. However, one thing has gone right, and that is the emergence of Sistani as a major power broker. He has been a moderating influence on Iraqi Shiites, a force for normalization of Iraq's politics, for state building and for the orderly transition of sovereignty. Early on Sistani encouraged Shiites not to resist U.S. entry into Iraq, and he has continued to caution his followers against militancy and preached calm in the face of provocations by those who have sought to ignite a Shiite-Sunni war. Sistani refuses to bend to U.S. will in drawing up a constitution, but that does not mean that he is not a force for positive change in Iraq.

Equally important, Sistani is also becoming a key leader with influence to determine political outcomes across the broader region. That is especially true in Iran, where struggles of power between hard-line clerics, reformers and civil society forces have reached a critical stage and are likely to boil over in coming years. Since the fall of Baghdad, the volume of religious taxes Iranians give to Sistani has risen considerably. As more Iranian pilgrims make their way to Shiite holy cities in Iraq, Sistani's influence is likely to grow. Sistani's quietist approach to politics, his rejection of Khomeini's views on theocracy and the Islamic republic's rigid attitudes toward enforcing Islamic law will make him an influential voice in his native Iran. Sistani has already put forth a new model for Shiite politics, one that is pragmatic, open to democracy, receptive to dealing with the United States and far more tempered in its approach to implementation of Islamic law than has been evident in Tehran. Iran's current revolutionary leadership lacks Sistani's spiritual stature, and as that country faces important decisions of constitutional reforms and the place of religion in politics, Sistani is likely to have an influence on the outcome.

It is crucial that U.S. policymakers take stock of Sistani's importance and the positive role that he can play in helping America realize its goals in Iraq and the broader region. The U.S. administration must look to strengthen Sistani. This means avoiding radicalizing Shiite politics, increasing Sistani's room to maneuver and making sure that he is able to maintain his legitimacy by delivering on the demands of his community, especially with regard to the constitution and the interim government that will take over on June 30. If he fails to do so, his brand of politics will give way to one that looks to confrontation rather than negotiation.

More importantly and immediately, the United States must allow Sistani to find a solution to the standoff in Najaf. If Sistani is able to preserve the sanctity of the city and prevent bloodshed while addressing U.S. demands, his stature will be enhanced immensely. This is ultimately what America wants -- to empower Sistani and to cage Sadr, to nudge the Shiite community away from combative posturing and toward constructive engagement over the constitution and future of Iraq. The imperative of reining in Sadr and his militia has to be balanced with the larger goal of achieving the U.S. objectives of bringing stability and order to Iraq. Preserving Sistani's position should matter more than crushing Sadr. Surely the United States would not want Sistani to become "collateral damage" in a showdown in Najaf.

The writer is a professor of Middle Eastern and South Asian politics at the Naval Postgraduate School.