Senior American officials say they are confident that Iraq’s draft constitution will be approved in the referendum to be held Oct. 15, even though Sunni Arabs in Iraq are mobilizing in large numbers to defeat it.
In testimony before Congress on Thursday, the senior American military commander in Iraq, Gen. George W. Casey Jr. of the Army, said the most recent analysis of intelligence from across the country supported the Bush administration’s optimistic predictions that the referendum would pass.
But if the constitution is defeated, several officials said they feared that Iraq would descend into anarchy.
Approval “is critically important,” a senior administration official said, “to maintain political momentum. That is the critical thing for holding this whole thing together.”
Private organizations in Iraq, many working with government financing, say their own analyses, based on discussions with hundreds of Iraqis, polling data and other information, have also led many of them to believe that the constitution would be approved.
Their calculations are complicated, because by law the constitution will fail if it is rejected by two-thirds of the voters in any three of Iraq’s 18 provinces, even if a majority of voters nationwide approve it.
In regions dominated by Sunni Arabs, opinion polls have shown sentiment running just about two to one against it. It is unclear, in those provinces, how get-out-the-vote campaigns by the opposing factions may tilt the balance, or how much the turnout on either side may be suppressed by the continuing violence.
But no matter how the vote goes, several officials said in interviews, the violence in Iraq is likely to increase significantly.
That prediction stands in contrast to the upbeat previous assessments from President Bush and others in his administration before other major turning points in Iraq, like the transition to Iraqi sovereignty in 2004 or the national elections early this year. The administration argued that insurgents would be demoralized by the success of democracy and that violence would decline.
Senator Carl Levin, Democrat of Michigan, asked General Casey in a pointed exchange during the hearing on Thursday, “If there’s a strong majority of Sunnis, which is very possible, that vote against that constitution, could that not possibly lead to a worsening political situation rather than a better one?”
“I think that’s entirely possible,” the general replied. “I mean, as we’ve looked at this, we’ve looked for the constitution to be a national compact, and the perception now is that it’s not, particularly among the Sunnis.”
Officials say that if the constitution is defeated, insurgents will most likely believe that they have won a significant victory and be encouraged to fight on. Conversely, it is said, the insurgency will grow stronger if the voters approve the constitution, because that will anger Sunnis who opposed it and empower Sunni insurgents who can claim that their views were ignored.
“A vote for the constitution doesn’t mean we’re headed for peace and prosperity,” Gen. John P. Abizaid, head of the Central Command, said in an interview this month. “Iraq is going to be a pretty difficult security environment for a while.”
A senior official said the Bush administration believed that the insurgency was likely to continue for years and would start to decline only “when Iraq’s political and economic system begins to consolidate.” The administration officials agreed to talk only if their names were not used, under administration policy for their departments.
Sunni Arabs, who held power when Saddam Hussein ruled Iraq, boycotted the election in January. But now, American officials and officers of private organizations working in Iraq say Sunnis are registering to vote in record numbers that exceed 80 percent in many areas.
“There’s a massive, massive effort, in mosques and other places, to get them to register,” the Iraq country director for the National Democratic Institute, said in a telephone interview on Wednesday. He asked that his name not be used, because of security concerns. The institute is an organization financed by the United States government that works to promote democracy abroad.
Many Sunni Arabs are upset that the draft constitution grants Kurds and Shiite Arabs significant new authority to set up semi-independent areas but offers little specifically for them.
Still, the country director and others say they do not believe that the Sunni vote is likely to be monolithic. Many Sunni moderates, they say, are likely to vote in favor of the constitution and hope to influence how it is put into effect. The constitution seems likely to be approved by substantial majorities in the heavily Kurdish north and the predominantly Shiite south. In ethnically mixed Baghdad, the situation is more fluid.
Senior Pentagon and military officials who have been closely monitoring reports from Iraq predict that the referendum will fail by the two-thirds majority in the Sunni-dominated – and violence-plagued – Anbar Province in western Iraq. But intelligence reports indicate that only one other province at most will vote no by two-thirds.
“Nobody will be surprised to lose Anbar, and maybe one other province,” one Pentagon official said. “We’re not going to lose three.”
American political and military officials say a large Sunni vote will be a sign that democracy is taking hold in Iraq. Still, the United States is working hard to be sure that the Sunni opponents will not prevail. Among many steps, State Department officials said, Zalmay Khalilzad, the United States ambassador to Iraq, is meeting with Sunni Arab leaders almost every day, trying to persuade them to vote yes.
Eric Schmitt contributed reporting for this article.