By Roger Hardy
BBC Middle East analyst
US Secretary of State Condoleezza Rice, is in the Middle East trying to win Arab support for the Bush administration's new strategy for Iraq and its tougher approach to Iran.
Arab states fear that the violence in Iraq is poisoning the region
So how successful is she likely to be?
The Arab rulers find themselves caught between the American eagle and the Iranian lion.
Washington's main Arab allies, Saudi Arabia, Egypt and Jordan, have watched the recent rise of Iranian power and influence in the Middle East with mounting trepidation.
But they are reluctant to be drawn into an anti-Iranian regional alliance led by an unpopular United States, especially if such an alliance tacitly included Israel.
In his speech on 10 January setting out a new US strategy for Iraq, President Bush had a blunt warning for his nervous Arab allies.
"Countries like Saudi Arabia, Egypt, Jordan and the (Arab) Gulf states," he declared, "need to understand that an American defeat in Iraq would create a new sanctuary for extremists and a strategic threat to their survival."
An Iranian envoy was in Saudi Arabia just ahead of Condoleezza Rice
It was in their interests to help America succeed in Iraq and to "prevent Iran from gaining nuclear weapons and dominating the region".
The arrest by the Americans of five Iranians last week in Kurdish-controlled northern Iraq suggests this is not mere rhetoric, but the start of a more confrontational approach to Iran.
But nervous though they are about Iran, Arab rulers may take some persuading that the new US strategy will make them safer rather than the reverse.
They have three interlocking fears:
Iraq's instability will get worse and the poison of sectarianism will spread beyond its borders
Confrontation between Washington and Tehran will lead inexorably towards some kind of US military strike against Iranian nuclear facilities - a move which would dramatically raise the regional temperature
Despite the Bush administration's claims that it is seriously engaged in efforts to revive the Arab-Israeli peace process, the current deadlock will persist.
In other words, they would be foolish to align themselves too closely with US policies which are not only deeply unpopular in the region, but doomed to fail.
The dilemma of the Saudi kingdom, which is wealthy but militarily weak, is particularly acute.
Moreover there have been signs of a rift between senior princes over what course to adopt.
The Foreign Minister, Prince Saud al-Faisal, is said to favour a cautious, non-confrontational approach to Iran.
The National Security Adviser and former long-time Ambassador in Washington, Prince Bandar bin Sultan, is thought to want a more aggressive posture.
In December, Prince Bandar's successor in Washington, Prince Turki al-Faisal (the foreign minister's brother), abruptly resigned, reportedly in protest at interference by the more hawkish Bandar.
How far this dispute is hampering coherent foreign-policy-making is not clear.
Iran, for its part, is anxious to maintain good relations with Saudi Arabia, and to avoid being accused of fostering Sunni-Shia tensions in the Arab world.
It is a complicated picture.
But the factor that will have the greatest impact on regional attitudes is not what the Iranians or the Americans may say, but what happens on the ground in Iraq.
If Arab fears of growing chaos are realised, they may be drawn willy-nilly into taking the side of Iraq's Sunni Arab minority against what they regard as a Shia-led, Iranian-backed government.
Iraq could become the new Lebanon, wracked by a lethal combination of civil war and external interference.