NEW YORK (AP) - Government officials say Russia, Iraq and North Korea are probably concealing the deadly smallpox virus for military use, The New York Times reported Sunday. A secret federal intelligence assessment was completed late last year. It was based on evidence that includes disclosures by a senior Soviet defector, blood samples from the North Korean soldiers that show smallpox vaccinations and the fairly recent manufacture of smallpox vaccine by Iraq, according to the report. Officials told the Times the assessment was an important factor in President Clinton's recent decision to reverse course and forgo destruction of American stockpiles of the virus.