BEIRUT Accusations of an Iranian plot to kill Saudi Arabia's envoy to Washington highlight the deepening Saudi-Iranian cold war for power in the Gulf, but some Middle East analysts questioned the evidence and timing behind the U.S. announcement.
Washington said Tuesday it had foiled a plot by two men linked to Iran's security agencies to assassinate Saudi ambassador Adel Jubeir, a close aide to King Abdullah. Iran denied the charge but Saudi Arabia said it would "pay a price."
The accusation follows tensions between U.S.-backed global oil giant Saudi Arabia and Iran over the upheaval sweeping the Arab world, with both countries suspecting each other of inciting unrest against them or their allies.
Shi'ite Iran's close Arab ally Syria has for six months been battling protests against President Bashar al-Assad, who blames the unrest in his country on foreign-backed armed groups.
Sunni Muslim power Saudi Arabia has faced protests in the Shi'ite Eastern Province and sent forces to neighboring Bahrain to help crush sustained demonstrations there by majority Shi'ites -- seen by Riyadh as proxies for Tehran.
"There is a secret war going on between the Saudis and Iranians and it does not surprise me that one of its battlegrounds could be the U.S. because of its major role in shaping policy toward the region," said Mohammad Masri, researcher at Jordan University Center for Strategic Studies.
"The Americans don't normally fabricate such reports and I suspect all this is tied to Syria ... The Saudis are perceived by Iran as actively involved in changing the Syrian regime."
Even before the Arab uprisings erupted, Saudi concerns over Iran's nuclear program -- which Tehran insists is for peaceful power generation -- and its influence in post-Saddam Iraq fueled hostility between the two rivals for power in the oil-producing Gulf region.
Riyadh's antagonism toward Iran was revealed in leaked U.S. cables that quoted Jubeir telling United States diplomats four years ago that the time had come to "confront Iran."
In 2008 Jubeir quoted King Abdullah as telling Washington to "cut off the head of the snake," referring to Iran.
But despite the chasm of mistrust between the two powers, analysts questioned whether Tehran would actually take the incendiary step of killing a senior diplomat on U.S. soil.
"I am not convinced that Iran would attempt to assassinate the Saudi ambassador in the U.S. There is no political use to it," said Mohammed Qadri Saeed, strategic expert at Cairo's Al-Ahram Center for Political and Strategic Studies.
Michel Naufal, foreign editor of Lebanon's al-Mustaqbal newspaper, said he had doubts about the timing of the charges if the United States had been aware of a plot for months.
"Why now? Obama was told in June," he said. "I don't think the Iranians have the capabilities to carry this out in Washington," he added.
The primary evidence linking Iran to the alleged conspiracy appeared to be that the suspect arrested in the United States had told law enforcement agents that he had been recruited and directed by men he understood to be senior officials of the Quds Force, a covert branch of Iran's Revolutionary Guards.
"The evidence is weak," said Lebanese analyst Nabil Bu Monsef.
The United States has led a global effort to isolate Iran and escalate United Nations sanctions in recent years, in response to what Washington and its regional allies including Saudi Arabia and Israel believe is a front for building nuclear weapons.
"If the reports are true ... then it shows Iranian desperation," said Jordan University's Masri.
"(It shows) they have started to feel the heat of regional developments and the more assertive Saudi policy in Syria."
But many Arabs remain skeptical about U.S. motives in a region where few have forgotten the flawed case made by Washington for invading Iraq to topple Saddam Hussein in 2003.
"Why is the U.S. raising this issue now?" said Walid Moubarak, professor of political science at the Lebanese American University. "Do they need a pretext to do something against the Iranians?"
(Additional reporting by Laila Bassam in Beirut, Suleiman al-Khalidi in Amman and Tamim Elyan in Cairo; Editing by Kevin Liffey)