The U.S.-Russian team also judged that it would be more than five years before Iran is capable of building both a nuclear warhead and a missile capable of carrying it over long distances. And if Iran attempted such an attack, the experts say, it would ensure its own destruction.

“The missile threat from Iran to Europe is thus not imminent,” the 12-member technical panel concludes in a report produced by the EastWest Institute, an independent think tank based in Moscow, New York and Belgium.

The report, scheduled for release today, could further dampen the Obama administration’s enthusiasm for a Bush administration plan to deploy radars and interceptor missiles in Poland and the Czech Republic.