If a US attack against Iran occurs, American forces in Iraq could end up virtual "hostages in Iran's hands," Lebanon's most senior Shi'ite Muslim cleric has warned. Grand Ayatollah Mohammed Hussein Fadlallah - a former Hizbullah spiritual guide still widely respected by many militants - says US President George W. Bush's war on terror has encouraged extremists, not curbed them, and has deepened Arab animosity toward America. "The American people must realize that their administration is not fighting terrorism but rather is causing it," Fadlallah told The Associated Press Tuesday. Fadlallah spoke at a mosque in Haret Hreik where he leads noon prayers, not far from where his house and office, located in the Hizbullah stronghold of south Beirut, were leveled by Israeli warplanes during last year's summer war between Israel and Iranian-backed Hizbullah guerrillas. He is the top religious authority for Lebanon's 1.2 million Shi'ites, believed to be the country's largest of 18 sects. The cleric - who often criticizes US polices in the Mideast - told the AP he thought a US attack on Iran was unlikely but he still had harsh words of warning. "I believe that the conditions in the region, the failure facing President Bush's policies in the region, and fears by (Arab) Gulf states that a war on Iran will probably destroy sensitive areas - especially oil wealth sources - makes an attack on Iran highly unlikely," the black-turbaned, white-bearded cleric said. But "in the event of a war on Iran, US soldiers in Iraq might become hostages in Iran's hands," he added. There are increasing worries among some Arabs that the US or Israel plans to strike Iran. Though Washington has said it wants to solve its differences with Teheran diplomatically, it has said it's not ruling out any options. The US and some of its Western allies believe Iran is using its civilian nuclear program as a cover for weapons development. Teheran denies this, insisting its nuclear program is for generating electricity, not developing a nuclear bomb. Washington also accuses Shi'ite-majority Iran of supplying Shi'ite militants in Iraq with deadly roadside bombs that have killed American troops - a claim Tehran also denies. In a show of defiance, Iran has staged large-scale military parades and made claims recently that its military would strike back if attacked. Last month, Gen. Mahmoud Chaharbaghi, the missile commander of Iran's elite Revolutionary Guard Corps, said the country was capable of firing 11,000 rockets into enemy bases within a minute of any attack. The US has tens of thousands troops in Iran's neighbors Iraq and Afghanistan as well across the Gulf and in Mideast waters. Fadlallah, 72, has emerged over the years as a prominent figure in Lebanese and regional politics. Some visiting foreign dignitaries have called on him, including most recently British Mideast envoy Michael Williams. He now lives in a renovated house adjacent to his destroyed residence amid rubble and shell-pocked buildings in Beirut's southern suburbs. A Lebanese born in the Iraqi city of Najaf, the spiritual heart for Shi'ites, Fadlallah was spiritual mentor for Hizbullah during the 1980s, when militants linked to the group were blamed for kidnapping Westerners and bombing American embassies and the Marine base in Beirut, killing more than 260 Americans. Hizbullah, which is listed as a terrorist organization by Washington, has denied involvement in the kidnappings or bombings. Fadlallah also has denied links to the bombings, though Western intelligence officials in the 1980s claimed he blessed the suicide drivers whose bomb-laden vehicles destroyed the Marine base and French military headquarters in Beirut in 1983. Fadlallah escaped a 1985 car bombing of his neighborhood that killed 75 people and wounded 256, an attack believed by many to have been masterminded by the CIA. In 1995, former US President Bill Clinton issued an order to freeze the cleric's US assets as part of an anti-terror campaign. Fadlallah has stopped being Hizbullah's spiritual guide about 20 years ago, and has regularly condemned terror attacks against civilians. He currently runs an Islamic charity with links to businesses such as schools, gas stations and a restaurant. But his ties to Hizbullah are not completely severed. He recently met Hizbullah's leader Hassan Nasrallah. "My relations with Hizbullah are good," he said Tuesday, without elaborating. Fadlallah has followers among Shi'ites in Iraq, the Gulf, Pakistan and India. He has accused the US of engineering the sectarian strife in Iraq and decried Sunni-Shi'ite violence there. Fadlallah has not visited Iran since his relations with Teheran's ruling clergy were strained more than a decade ago over who represents the religious authority for Shi'ites in Lebanon and abroad. Asked about his relations with Iran, Fadlallah said Tuesday he has "a standing invitation to visit Iran." But he added without elaborating that "the current circumstances do not allow me to make the visit now." A militant in the eyes of the West, Fadlallah has taken some progressive, nonviolent positions on some issues, raising eyebrows among some of his conservative followers. Fadlallah has condemned honor killings, a practice common in some conservative Muslim communities, called for a peaceful boycott of American products, banned smoking as a religious duty and approved cloning for scientific research purposes.