By Roger Hardy
BBC Middle East analyst
In the run-up to the referendum on Iraq's new constitution, there are growing anxieties among the country's neighbours.
Iran's Foreign Minister has sought to reassure Iraq's neighbours
Is Iraq on the verge of break-up? Has it swung firmly into the orbit of Shia Iran? Will the violence in Iraq spill over into other countries?
Iran's new foreign minister, Manouchehr Mottaki, is on a mission of reassurance.
He has been telling his counterparts on the Arab side of the Gulf that they have no reason to fear Iran's intentions - or its new, more conservative government.
At the heart of his message is that Iran, like the Arabs, wants to see a stable Iraq, free of foreign interference.
But the Arab states, and for that matter Turkey, are not reassured.
They feel that the main beneficiary of the toppling of Saddam Hussein, and the rise of a Shia-dominated government in Baghdad, is Iran.
The sight of an Arab government dominated by Shia and Kurdish ministers has come as a shock
The Saudi foreign minister, Prince Saud al-Faisal, was recently in Washington warning darkly that violence and sectarianism in Iraq could lead to its disintegration.
He then delivered the same stark message to a meeting of Arab ministers - and was roundly rebuffed by Iraq's interior minister, Bayan Jabr.
Mr Jabr, a Shia with close connections to Iran, denounced the Saudi kingdom's treatment of its women and its Shia minority.
And for good measure he called the Saudi prince a "bedouin on a camel".
'Sunni order' challenged
Such verbal exchanges between Middle East neighbours are not, of course, unprecedented.
But behind the insults lurk serious issues.
Most of Iraq's neighbours were unhappy about the US-led invasion of Iraq in 2003.
They had no great love of Saddam Hussein, but were worried about the regional consequences of the war.
In many ways, the fallout has been even worse than they had feared.
The Americans and their allies appear to be bogged down fighting an insurgency which could drag on for years.
Prince Saud al-Faisal has warned the US about the situation in Iraq
While Sunni Arabs in the region have some sympathy for what could be called the nationalist element within the insurgency, they are troubled by the ultra-violent "jihadi" element.
They are afraid that the Arab militants who have entered Iraq to join the insurgency will one day go home to make trouble.
Moreover the Arab world has traditionally been run by a Sunni Arab elite.
The sight of an Arab government dominated by Shia and Kurdish ministers has come as a shock.
Some even see a new threat to the regional "Sunni order".
Such fears may be exaggerated.
The new power of the Iraqi Shia is certainly being watched with close interest by Shia elsewhere in the region.
But, so far, the effect has been to stimulate a kind of cultural renaissance, a heightened sense of Shia consciousness and identity.
Whether this will translate into greater political power - for example, for Saudi Arabia's Shia minority - is an open question.
As for Iran, its intentions in Iraq remain ambiguous.
Since the fall of Saddam, it has strengthened its religious, cultural and economic ties with Iraq's Shia majority.
It has cultivated close relations with all the main Shia political parties and their militias.
Less clear is whether it is actually fomenting anti-American violence, as some US officials have alleged.
Even if it is not, Iraq's neighbours believe that America has wittingly or unwittingly changed the regional balance of power in Iran's favour.
And they believe they, and the Americans, will suffer as a result.