Washington ? The U.S. acknowledged Friday that Iraq is spiraling downward, with sectarian animosity growing and new Iraqi troops being added too slowly in a precarious mix that could draw the country’s neighbors into the violence if American troops leave.

The sobering assessment from the National Intelligence Council was seen by congressional Democrats – and some Republicans – as new evidence that President Bush’s Iraq policy is failing.

“I do not see anything so far in the report that suggests the president’s new plan is a winning strategy that protects America’s national interest,” said Senate Majority Leader Harry Reid, D-Nev.

Yet top Bush administration officials said the intelligence assessment reinforced their view that the United States cannot leave Iraq. At a news conference, Defense Secretary Robert Gates said he knew no one on Capitol Hill who believed that leaving the country in chaos “would have anything other than very serious and negative consequences for the United States and for the region.”

Indeed, the report suggested that a pullout of U.S. troops could draw Iraq’s neighbors into the violence.

Friday’s newly declassified portions of a National Intelligence Estimate on Iraq concluded that Iraq’s security situation is likely to get worse over the next 18 months unless the slide toward sectarian polarization and a weakening government is halted. Security forces – particularly the police – will be “hard-pressed” to handle their new responsibilities because of divisions that are tearing apart Iraqi society, the assessment said.

Any further negative event such as the assassination of a religious leader could hasten deterioration, it said. “The challenges facing Iraqis are daunting.”

Gates said the extra troops that Iraq promised to send into Baghdad as part of a new U.S.-Iraqi military buildup are arriving in insufficient numbers. His outgoing commander in Baghdad, Gen. George Casey, has said the arriving Iraqi units have only 55 percent to 65 percent of their intended troops.

Defense Secretary Robert Gates, left, accompanied by Joint Chiefs Chairman Gen. Peter Pace, speaks during a news conference Friday at the Pentagon. Gates said the extra troops that Iraq promised to send are coming in insufficient numbers.

“Fifty-five percent probably isn’t good enough,” Gates said.

The problems facing Iraqi security forces are as basic as ensuring that troops can feed their families. The Iraqi government pays troops’ salaries in cash, forcing them to return home to deposit their earnings. That, Gates said, increases absentee levels.

The intelligence assessment painted a picture of a country hanging in the balance.

Top U.S. intelligence analysts found that even if violence diminishes, Iraqi leaders will find major difficulties in reconciling differences among various sects. The analysts attributed it to a “winner-take-all attitude and sectarian animosities infecting the political scene.”

Knowing the findings were likely to become public, intelligence analysts stepped gingerly around one of the most politically charged questions of the Iraq debate: Is the country in the midst of a civil war?

The analysts found the term “civil war” doesn’t entirely capture the complex situation in Iraq. In addition to Shiites fighting Sunnis, the country is also facing attacks on U.S. and coalition forces and struggles within ethnic and religious sects.

Yet the estimate said the term “civil war” does reflect key elements of the conflict: the hardening of sectarian identities, changes in the nature of the violence and the geographic displacement of significant segments of the population.