Global Policy Forum

By Douglas Jehl and David E. Sanger*

Early this year, American spy satellites detected a spike in suspicious tunneling activity at a highly secretive military site in the mountains of North Korea. It alarmed some of the government's top nuclear analysts, who saw it as a sign that North Korea might be preparing to make good on threats to conduct its first test of a nuclear weapon. There was even tantalizing talk among some officials in Washington that the North Koreans were so far along in preparing for an underground detonation that they had built a reviewing stand for dignitaries to witness the earth tremble.

The prospect of an imminent test became a crucial point in briefings by the Bush administration to its Asian allies and China, arguing that the North Korean threat was growing rapidly and that they needed to increase pressure to resume six-nation talks aimed at disarmament. After weeks of diplomatic maneuvering, North Korea agreed to resume the talks, which are to begin Tuesday.

But behind that urgent view of North Korea's activities lies a much more complicated, and at times contradictory, picture. It shows some of the same strains over the use of intelligence that came to divide federal agencies and policy makers before the Iraq invasion.

In a classified briefing on April 26, at about the same time Washington was warning its allies, the Central Intelligence Agency told Congress that it was unlikely that North Korea would conduct a nuclear test anytime soon. Moreover, the White House had assessed the probability of a North Korean test this spring as relatively low, officials say. And they say that the claim by some analysts and administration officials of a reviewing stand, which was reported in a front-page article in The New York Times and then by several other news organizations, was apparently based on misinterpretations of inconclusive or incomplete data and should not have been circulated outside the government.

North Korea's true intentions on testing - whether the activity in the mountainous Kilju region was genuine or an attempt to deceive the world - may never be known. But a review of this spring's divergent assessments, based on interviews with officials from Congress, the administration, American intelligence agencies and foreign governments, reveals how the process of assessing North Korea's weapons is vulnerable to politics and to the imprecision of intelligence. Most of the officials and analysts spoke on the condition of anonymity because the subject concerned classified information and issues of political sensitivity.

The limitations of intelligence-gathering are particularly acute with North Korea, which one former senior State Department official described as the blackest of black holes. The West has few, if any, spies there and the North Koreans are famous for their strategy of deception. Most of the intelligence driving the two assessments was obtained by satellite, leaving it open to conflicting interpretations, or agendas.

Fears About a Nuclear Test

The question of whether North Korea would conduct a test had great significance because, many experts and officials fear, such a step could ignite a nuclear arms race in Asia. If the more urgent view of the test preparations was circulated by the Bush administration as it sought to restart the six-nation talks, the more benign version was promoted by the C.I.A., which is struggling to overcome criticism for overestimating Iraq's unconventional weapons. Although the government overhauled its sprawling intelligence structure in the wake of 9/11 and the Iraq war, the North Korea episode highlights a lingering lack of coordination in assessing even the most serious threats.

While the C.I.A. briefing to Congress was explicitly represented as the view of the full "intelligence community," it apparently did not reflect the more urgent views of nuclear intelligence analysts in the Energy Department and the Pentagon, according to people present. And foreign allies did not hear the same message contained in the "intelligence community" version, that is, that a test was unlikely.

The White House and the Pentagon, as well as some nuclear weapons experts at the Energy Department, described the level of tunneling and other activity at the suspected test site as unprecedented. But the C.I.A. and the State Department said that while the activity was high, they judged it as within the pattern of peaks and valleys that had occurred over the previous year. The C.I.A., citing political factors, also said it believed that a test was not imminent because such a step would anger China and be a major escalation in North Korea's confrontation with the West.

Some Congressional and intelligence officials drew parallels between elements of the North Korea assessment, particularly the unverified reports of a reviewing stand, and the handling of some of the prewar intelligence on Iraq's weapons and Al Qaeda connections by administration officials.

The information about the reviewing stand was not part of the formal briefing to allies but was relayed informally, officials said. While it was considered a far less significant warning sign than the increased tunneling, one administration official said, it was "easy to understand."

After the claims of a reviewing stand were reported on May 6 in The Times, Pentagon officials repeated them, including to several foreign newspapers, most notably in South Korea. But the claims were never cited in formal intelligence assessments or mentioned in the C.I.A.'s closed briefing to the Senate Intelligence Committee in April. Senator Pat Roberts of Kansas, the Republican chairman of the Senate panel, said in an interview that the committee had studied the reviewing stand claims and determined that there was "no there there."

Ultimately, said officials involved in the process, the judgment of North Korea's activities seem shaped both by the expertise of analysts and the assumptions of policy makers about what North Korea is up to. Arthur Brown, who retired in February as the head of the directorate of operations for Asia at the Central Intelligence Agency and who spent more than 20 years studying North Korea, said the divergent assessments were not surprising. "People throughout the intelligence world are on the defensive; they want to be very careful," he said.

Plans for an Arsenal

North Korea's dream of a nuclear arsenal dates back a half century, to the years just after the Korean War. Recently declassified documents show that Kim Il Sung, North Korea's founder, pressed his cold war allies - first Russia, then China - for nuclear technology. By the early 1990's, Mr. Kim appeared to have achieved his goal of building one or two atomic weapons. But for American intelligence officers tracking North Korea's progress, the assessment, in the words of one former senior official, was "one part intelligence, one part logic, one part educated guess."

At times, American intelligence has fallen victim to North Korea's clever deceptions. In 1998, the Clinton administration demanded access to a huge underground site that a military intelligence agency believed was a nuclear reactor. The North Koreans reluctantly agreed, in return for aid. But when an American-led inspection team got there, they found the cavernous site empty and improperly configured for a reactor.

After President Bush took office he cited North Korea, now run by Kim Jong Il, as part of the "axis of evil" and ordered intelligence agencies to work hard on assessing its threat. A senior intelligence official said that in 2002 alone, the agencies produced three National Intelligence Estimates, classified documents meant to reflect the combined judgment of the entire intelligence community. Among other topics, they addressed North Korea's ability to produce bombs from spent reactor fuel.

Last year, a new concern emerged. Signs multiplied that North Korea might be preparing for a nuclear test, which would shatter any doubts about its atomic prowess. American satellites, monitoring about a half-dozen suspicious sites in North Korea, focused on rising activity in the rugged hinterlands of the Kilju region, where a tunnel entrance had been gouged into the flank of a high mountain.

It was one of many mysterious tunnels. "They are mole people," said Mr. Brown, now an executive at Control Risks Group, an international consulting company. "There are hundreds, thousands of holes in the ground, and we don't know what's in them." Some are mines, American officials say. Others could protect military planes from attack, or house elements of a nuclear program, the officials say.

Last year, as disagreements arose within the government over interpretations of the evidence, the directors of the nation's three nuclear weapons laboratories, run by the Energy Department, were convened for a top-secret assessment, according to an official familiar with the study.

Sounding an Alarm

While Energy Department analysts saw the tunneling activity as a possible prelude to a test, the Bush administration said little at first, perhaps because it was tied down in Iraq, according to current and former intelligence officials and diplomats. Eventually, the president and his aides decided to sound the alarm because of the potential global political ramifications, administration officials said. They also had their eye on domestic politics.

Last October, fearing a pre-election test, the White House revealed the activity to The Times, conceding that it was uncertain whether North Korea was preparing for an explosion, or merely bluffing. In January, more activity set off a similar scare at the White House, which did not reveal its concerns, according to a senior administration official.

This spring, more movement at Kilju touched off the latest round of assessments. In each of those scares, the intelligence community has been divided, perhaps reflecting powerful yet contradictory lessons of past mistakes. Since Iraq, Congressional investigators and a presidential commission have warned against the dangers of overstating intelligence. Yet in some quarters, officials say, an equally powerful lesson is the failure of American intelligence agencies to detect nuclear test preparations in India in 1998. "The way the community is working," said a senior nuclear intelligence official, "they evaluate the present through the lens of the most recent catastrophe."

The Defense Intelligence Agency and the Energy Department, which missed the 1998 test evidence, have been among the first to raise alarms about North Korea. Analysts at those agencies tend to look largely at satellite imagery, comparing it with tests in Pakistan and China - two of North Korea's nuclear suppliers.

The C.I.A. has been far more cautious, saying that the evidence could point to a "denial and deception" operation or to nonnuclear testing, or simply a nuclear project in its early stages. The State Department's intelligence arm, which, like the C.I.A., is particularly attuned to the political implications of a test, has also expressed doubts.

Even for some scientists, assessing North Korea is more art than science. One government expert on nuclear testing said the Kilju intelligence made it look like the North Koreans were in final preparations for a test because material was being put back into the tunnel, suggesting that it was being sealed for a detonation. But on balance, he judged it a ruse."A large component of what they do is designed to get a predictable reaction," he said. "It's a small investment. They've given us all the indicators of something that might not be happening."

Assessing the Intelligence

At the White House and the C.I.A. this spring, there were several meetings to assess the latest satellite imagery. North Korea experts - inside the government and out - said they were especially concerned since what appeared to be preparations came in the context of brash provocations by the North Koreans.

On Feb. 10, North Korea publicly declared itself a nuclear weapons state. It demanded that the six-nation disarmament talks become mutual arms reduction talks with the United States - like those Washington used to hold with the Soviet Union. In April, it shut down its main nuclear reactor - raising fears that it was making good on threats to harvest nuclear fuel for more bombs.

Even so, inside the government, the emerging consensus seemed to be against the likelihood of a test. On April 26, a C.I.A. briefer told the Senate Intelligence Committee that the tunneling was "consistent" with a possible test, said government officials with detailed knowledge of the session, but that a detonation was not likely any time soon. There was no mention of a reviewing stand.

Senator Roberts would not discuss the contents of the briefing, but he said he knew of nothing specific that would have led analysts to warn that North Korea was moving closer to testing. The traditional C.I.A. view is that North Korea tends to escalate its provocations toward the West incrementally, and that a nuclear test would be an extreme step. "Once they do that, they have nothing left," the United States official said.

The C.I.A. briefing of the Senate committee was overseen by the national intelligence officer responsible for issuing warnings about impending threats, an indication that it had the imprimatur of the wider intelligence community. Even so, there was no mention of dissenting opinions within that community - particularly from the Energy Department and the Defense Intelligence Agency. Those dissents appear reminiscent of the fierce behind-the-scenes arguments over weapons in Iraq, which only came to light after the American invasion.

One senior official involved in the assessment recalled that "there were various camps and groupings, but I don't remember there ever being a consolidated community view." Such views are usually worked out in the process of writing National Intelligence Estimates, but apparently none on North Korea has been done this year, according to several intelligence officials.

In its own deliberations, White House officials were also cautious. A senior administration official said they concluded that the chances of an imminent test were low to somewhat higher than low, chiefly because a test would so anger the Chinese - the North's only significant supplier of food and fuel.

Still, around the time of the Senate briefing, administration officials - including Stephen J. Hadley, the national security adviser - concluded that the United States' crucial negotiating partners had to be informed. But the briefing they received, while based on the same intelligence, left a different impression.

Officials in Tokyo, Seoul and Beijing - and some foreign diplomats in Washington - heard what one American official called a "more stripped down" version, focusing on activity detected by satellites. The contents of the briefing are confidential, but officials of several countries familiar with it said it contained little of the political analysis of North Korea's intentions, and left open the question of timing. They said their impression, therefore, was that North Korea might conduct a test quite soon. That impression was bolstered by the talk of the reviewing stand, which one American official acknowledged was "all over the place," even if it was not part of any official briefing.

It is unclear where that talk originated. One senior administration official said he believed that an image was initially "misinterpreted" as part of the suspected test site. Since that raw intelligence was not included in any formal reports, it appeared not to have been subjected to the kind of intense, multiagency vetting that verified intelligence receives. Officials who initially spoke about the reviewing stand, and described it as luxurious, backed away beginning in late May after The Times asked further questions, saying additional reviews of the evidence raised serious doubts about the whether the structure was a reviewing stand or even related to the test site.

Some officials apparently quickly dismissed the notion of a reviewing stand for an underground test. But others were predisposed to look for one because of another past intelligence failure: after American officials missed preparations for a 1998 North Korean missile test, they later found that one overlooked signal was the construction of a reviewing stand in the weeks before the test.

Analysts also observed other "V.I.P. preparations" around Kilju, according to several officials familiar with the intelligence, including a helipad and housing that was luxurious by North Korean standards, although officials later said it was at least a year old.

Warnings by the Allies

After the urgent briefings of allies, which made headlines in the United States and Asia, officials in Seoul, Tokyo and Beijing issued warnings to North Korea not to test. The South Korean foreign minister, Ban Ki Moon, said North Korea would "further deepen its isolation" if it took "such reckless actions."

On May 15, Mr. Hadley publicly warned North Korea for the first time against testing, saying the United States and several Pacific powers would take punitive action. "We have seen some evidence that says that they may be preparing for a nuclear test," he said on "Fox News Sunday." "We have talked to our allies about that."

Officials in the office of John D. Negroponte, the new director of national intelligence, whose mission is to coordinate intelligence functions, declined to discuss specifics of the North Korea case. But they said the National Intelligence Council was putting in place a system to identify and resolve important differences between agencies on crucial issues like North Korea, while still encouraging debate.

So far, North Korea has not conducted a test. After the warnings to the North Koreans, several diplomatic moves - including offers of food and electrical power - helped bring the North back to the long-stalled talks, although many experts predict that if the talks fail, the North may conduct a test, or threaten to.

The most recent satellite images of the Kilju show that the suspicious activity has subsided. But analysts, typically, are unsure what that means. The site could be unrelated to nuclear activity. And a senior nuclear intelligence official said it might also indicate that a bomb was buried and ready for testing, or that the North Koreans had accomplished what they wanted - a deception that roused the West to diplomatic action."They know that this is being looked at intently," he said. "Maybe they achieved what they wanted."

Douglas Jehl, David E. Sanger and Thom Shanker reported from Washington for this article, and William J. Broad from New York.