WASHINGTON — Although convinced that Iran is "vigorously" pursuing programs to produce nuclear, chemical and biological weapons, the U.S. intelligence community has few sources of reliable information on any illicit arms activities by the Islamic republic, current and former intelligence officials and Middle East experts say.
The United States has struggled to get more than glimpses and incomplete accounts of Tehran's weapons programs, they say, despite the fact that American spy agencies are in a better position to collect information on Iran since U.S.-led invasions and occupations of two of the country's neighbors in the last three years.
The dearth of quality intelligence has complicated American efforts to convince other nations to more aggressively confront Iran, and accounts for the caution expressed by some U.S. intelligence officials last week when Secretary of State Colin L. Powell said he had seen important new evidence that Iran was pursuing ways to mount a nuclear warhead on a missile.
"There are parts of the Iranian world that are not impenetrable," said a former senior CIA official who left the agency several months ago. The CIA and other U.S. spy services have been able to get a steady stream of reports on political developments inside the regime, he said, and have had some success tracking Iran's support of terrorist networks, including Hezbollah.
But Tehran "is particularly controlling and tight" in maintaining secrecy around its nuclear, biological and chemical weapons programs, the former official said.
"As with any country that may be pursuing WMD," he said, referring to weapons of mass destruction, "that's the most difficult nut to crack."
The combination of the hard-line U.S. diplomatic stance and the scant underlying intelligence has prompted comparisons to the United States' flawed case for war against Iraq. Despite the parallels, officials and experts said they believe there were important distinctions.
"We have so much more access to Iran" than U.S. intelligence did to Iraq before the war or to North Korea currently, said a congressional official with access to classified intelligence reports.
The official noted that significant numbers of Iranians travel abroad and that Iran is more open to outside visitors than either Iraq or North Korea.
"The window into Iran is much better," the official said.
Indeed, a secret CIA station in Los Angeles for years has cultivated contacts with members of the large Iranian population in Southern California, seeking information from those who have returned from trips to Iran or are in contact with relatives there, former CIA officials familiar with the program say.
Intelligence officials also note that unlike in Iraq, where inspectors searched the country before the U.S. invasion and found no evidence of ongoing illegal weapons programs, United Nations inspectors over the last year have confirmed that Iran has built facilities capable of enriching uranium, the main ingredient in a nuclear bomb.
Tehran says the facilities and equipment are for providing nuclear energy for peaceful, civilian use. Many U.S. analysts and experts doubt that explanation.
On Friday, the International Atomic Energy Agency, a U.N. watchdog, reported in Vienna that Iran and three European nations were near agreement on Iran's suspending programs to enrich uranium using centrifuges, a process that can provide material for either power generation or nuclear weapons. An earlier agreement with Britain, France and Germany appeared to unravel this week when Iran insisted on allowing 20 centrifuges to continue operating.
This week, the CIA released a report concluding that Iran has "continued to vigorously pursue indigenous programs to produce nuclear, chemical and biological weapons." In particular, the report says the U.S. "remains convinced that Tehran has been pursuing a clandestine nuclear weapons program" and that Iran "received significant assistance" from the nuclear proliferation network headed by Pakistani scientist Abdul Qadeer Khan.
Iran has pledged to suspend enrichment activities, but some U.S. officials are concerned that it will continue nuclear weapons work at hidden locations. Although inspectors have visited Iran's declared sites and gathered valuable information, "they don't have any access to facilities that are undeclared or covert," a CIA official said. "Inspectors inspect what they're allowed to inspect."
The suspicion that Iran may have secret nuclear facilities would be a major complication if the U.S. or another nation were to attempt to disable Iran's program with military strikes. The Bush administration has not proposed such an extreme measure and so far has backed European leaders' efforts to negotiate with Tehran.