If the draft constitution becomes reality, the new Iraq would be a vastly different place: a multicultural, democratic oasis where torture victims can sue their oppressors, free speech is protected and women gain a big role in government.
But Iraq also would become a decentralized, even fragmented, land in a volatile region, where neighbors such as Iran could easily exploit such weakness.
Key parts of the draft — on the role of private militias, the control of oil money and even Islam's impact on women's rights — could sow the seeds of conflict or, as a worst case, civil war.
Such fears lie at the heart of complaints by Sunni Arabs, who angrily rejected the draft Monday night, prompting parliament to suspend a vote to give time for passions to cool.
In a statement Tuesday, the Organization of the Islamic Conference, which includes all Muslim countries, urged Iraqis to produce a constitution with "consensus" — meaning Sunni approval.
The statement called for a charter that opens "new horizons for happiness and prosperity" instead of "sowing the seeds of future internal disagreements and conflicts."
Much of the draft would win plaudits in the West. It declares that no law "may contradict democratic standards." In a concession to secularists, Islam is declared "a major source" of the country's national laws, rather than the only source, as religious Shiites and Sunnis wanted.
Freedom of expression is guaranteed. Torture "and inhumane treatment" are banned, and victims have the right to sue for compensation. One in four seats in the legislature are reserved for women, and minority groups like Turkomen and Assyrians are accorded legal recognition.
But the document also contains provisions described by Sunni Arab negotiator Saleh al-Mutlaq as "land mines." His concern springs from Sunnis' status as a minority group facing the loss of centuries of privilege — and fearing retribution from other groups victimized under Saddam Hussein's Sunni regime.
For Sunnis, the biggest risk is turning Iraq into a decentralized federal state. Supporters insist that is the best guarantee against a new dictator, the same argument used by the West Germans when they created a decentralized government after the collapse of Adolf Hitler's regime in 1945.
But Sunni Arabs fear it would lead to the breakup of Iraq — or at least leave the country with a weakened central government, deprived of oil wealth and unable to defend itself against pressure from Iran, Syria and Turkey.
A provision that allows provinces to join together into an autonomous region could pave the way for a giant quasi-nation in the Shiite-dominated and oil-rich south. It also might lead to the expansion of the Kurdish self-ruled area in the north.
Kurds rule themselves in three provinces, a status accepted by Sunni Arab negotiators. But the Kurds have long demanded extension of their borders into Sunni-populated districts, including the northern oil center of Kirkuk.
Such autonomous regions raise a host of troubling issues.
The draft gives the central government authority over oil and natural gas "extracted from current wells." The implication is regional governments would play a greater role in future finds.
Regional governments also would have the right to establish their own internal security forces. That appears to be a concession to the Kurds, who insist their peshmerga fighters are not a militia but a legitimate regional defense force.
But the Shiites could use the same argument to have their own militia, the Badr Brigade, which attacked Iraqi targets from Iran during Saddam's regime. Or they could use it to justify the Mahdi Army of radical Shiite cleric Muqtada al-Sadr, which fought bloody battles with American troops in the past.
Shiite regional security forces, many of whose members have close ties to Iran, could wind up with responsibility for controlling the border with Iran, the giant, Shiite-dominated neighbor that fought a war with Saddam's Iraq in 1980-88.
Even if regional security forces exercised their power with professionalism, the very existence of armed forces organized along religious or ethnic lines almost inevitably would cause tension between Shiite parts of Iraq and Sunni-dominated neighbors like Syria and Jordan.
Islam's role in government also might be greater in an autonomous region controlled by religious Shiite parties, leading perhaps to fewer or different legal rights for women despite guarantees in the national constitution.
Inevitably, the creation of a Shiite autonomous area "favors religious Shiites over the more secular ... and mixed families," said Anthony Cordesman, an Iraq expert at the Center for Strategic and International Studies in Washington.
It also would likely provoke Sunni religious militants, who view Shiites as "near-apostates," Cordesman said.
The result, he believes, would be even deeper divides among Iraq's people.