In the last few days, Mr. Bush and other top U.S. officials have highlighted the dangers of last week's Persian Gulf ship confrontation, claimed that Iranian attacks inside Iraq are again spiking, and pointedly labeled Iran the worst state terror sponsor.
The tough words seem aimed at assuring both Arab allies and Israel that the United States remains intent on pressuring Iran, despite last fall's U.S. intelligence estimate that concluded.
In the report's wake, Mr. Bush faces a genuine challenge trying to keep strong international pressure focused on Iran, amid Russian and Chinese desires to ease up. Iran's promise, announced Sunday, to shortly answer remaining United Nations' questions about its past nuclear activities is likely to give the two more ammunition to forestall a new U.S. push for sanctions.
The danger is that the public U.S. confrontation, if it lacks credible factual back-up, will turn off the very European allies the United States seeks to convince. France, Germany and Britain are likely to stay allied with Mr. Bush on Iran, but only as long as they believe the United States has compelling evidence of Iranian wrongdoing.
The fierce Iranian-U.S. squabbling also poses a danger of spilling over into real conflict, perhaps by accident, as jittery U.S. Navy leaders in the Gulf's narrow Strait of Hormuz try to gauge Iran's intentions in real time.
Coincidentally or not, the last time Iranian-U.S. tensions spiked so high came after Vice President Dick Cheney - speaking aboard an aircraft carrier in the Gulf in May - issued a strong warning to Iran to back off on its nuclear program.
Complicating matters, Iran's motives remain as murky as usual.
Struggling hardline President Mahmoud Ahmadinejad may be looking anew for confrontations with the United States as he tries to build political support before March parliamentary elections.
Ahmadinejad often gets a popularity boost from U.S. tensions, as nationalistic feeling temporarily papers over the sharp disputes among Iran's factions. Under attack from many sides, Ahmadinejad badly needs such a boost to retain any real domestic influence during his last year and a half in office before he must seek re-election.
Iran also may be sending a message to Arab neighbors that it will not tolerate total U.S. control in the key Gulf waters, through which much of the world's oil flows.
After the Jan. 6 confrontation, when five small Iranian boats swarmed in a threatening manner toward three U.S. warships, U.S. Defense Secretary Robert Gates revealed there had been- "maybe not quite as dramatic" - over the last year.
None had been publicized until Mr. Bush's trip.
Iran and the U.S. each released videotapes vying to show their version of events. In the U.S.-released audio recording, a man threatens in accented English, "I am coming to you. ... You will explode after ... minutes."
On Sunday, however, the commander of one American ship, Cmdr. Jeffery James of the destroyer USS Hopper, said the threatening radio message may have been a coincidence. U.S. Navy officials said they had not yet determined where the message came from.
The Navy Times, a privately-owned newspaper, reported that some Navy sailors thought the threatening broadcast could have come from a heckler, widely known among sailors in the Gulf since the 1980s, who often taunts ships over open radio frequencies.
Also still unclear was the information, made public Saturday by the top U.S. commander in Iraq, Gen. David Petraeus, that attacks in Iraq linked to Iranian explosive devices had increased by a factor of two to three in the first 10 days of January. Such Iranian-linked attacks had dropped sharply last fall.
U.S. military officials said Monday they did not yet know if that constituted a sustained trend, but viewed it as significant. U.S. military reports in Iraq have so far shown no spike in deaths in the predominantly Shiite areas where the explosives, called EFPs, have been mostly used.
Despite such uncertainties, there is real fear in the region toward Iran and many hopes pinned on U.S. protection.
Businessman Khaled Mubarak al-Kendi said while some Arabs don't like Mr. Bush: "For us in the Emirates, it's very important to have a good relationship with the U.S., because only the U.S. can keep stability, especially when it comes to Iran."
The danger, said Joseph Cirincione of the liberal Center for American Progress in Washington, is that the administration may have "needlessly hyped a threat for political purposes - and further undermined American credibility in a crucial region."
Analysis by Sally Buzbee, Chief of Middle East News for The Associated Press.
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