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The global jitters over suspected North Korean preparation to test a ballistic missile have underscored how little the world knows about Pyongyang's intentions, its missile capabilities or even what kind of rocket fuel it uses.

The United States has insisted since last week that, at the very least, intelligence is fairly certain the reclusive communist regime has taken steps to ready a launch of a long-range missile, most likely a Taepodong-2 with an estimated range of up to 9,300 miles.

Beyond that, it's all guess work.

A key question has been whether the North Koreans have completed the crucial step of fueling the missile, which analysts would consider a significant sign Pyongyang is serious about a launch.

CountryWatch: North Korea

Some experts say the fueling question is especially pertinent because certain fuels could quickly corrode the inside of the missile, meaning the North Koreans would have to launch it within a fixed period or risk damaging it.

Others, however, say Pyongyang has plenty of time.

"The fuel can corrode the components in the missile, but that would take months not days," said Duncan Lennox, editor of Jane's Strategic Weapons Systems. "We don't know precisely what fuel they're using."

Amid such unanswered questions, many are looking at North Korea's past launches for clues about how the current crisis will unfold.

Pyongyang tested the Nodong 1, with a range of about 620 miles, in 1993. Five years later, it shocked the world by firing the more advanced Taepodong-1 missile over Japan into the Pacific Ocean.

Narushige Michishita, senior research fellow at Japan's National Institute for Defense Studies, said the North Koreans this time could test either a two- or a three-stage rocket. It could either be a satellite-launch vehicle or an offensive missile.

While an SLV would have technical downsides for Pyongyang, it would at least give the North Koreans cover for the rationale they offered in 1998: that the effort is part of a peaceful program.

"The upside is that they can exercise plausible deniability by saying, `We are not testing a missile, we are simply launching a satellite,'" Michishita said.

The range of North Korea's missiles are crucial — especially for the United States, which is concerned about whether Pyongyang has the capacity to hit Alaska, Hawaii or even the West Coast with a weapon.

Analysts are all over the map on ranges. Jane's, for example, issued a report last year saying the Taepodong-2's maximum range was probably about 3,700 miles, but a Russian report said it was about 5,600 miles, and an American report suggested 6,200 miles. Other reports have quoted U.S. officials as saying the 116-foot-long missile has a firing range of 9,300 miles.

Even further beyond the reach of certainty is the question of whether North Korea can make a nuclear warhead — if it has nuclear weapons at all — small enough to fit on the tip of its rockets.

The Japanese have publicly said they doubt it.

"At this point, we have encountered no information that indicates North Korea has the technology," Senior Vice Foreign Minister Yasuhisa Shiozaki said this week.

But Robert Dujarric, a North Korea expert in Tokyo, said the United States by 1953 was able to develop a bomb small enough to fit in a cannon bay — only eight years after exploding its first atomic weapon.

The disparity in opinion about the state of North Korea's missile program is testament to the country's considerable penchant for secrecy and deception.

Much of the regime's technological work is done underground. And when North Korea feels the eyes of the world are peering too closely, it simply shuts the door: International Atomic Energy Agency inspectors, for instance, were thrown out of the country in 2002.

One key to figuring out what North Korea will do is accurately gauging its intentions — another highly speculative game.

The general assumption is that Pyongyang is pushing for direct talks with the United States, and North Korean officials this week have suggested as much. But how far are they willing to go? And do they really think a missile test will achieve that goal?

Miscalculation by Pyongyang is another variable.

"The danger in the current predicament is that North Korea may misjudge or underestimate the resolve/intentions of the Bush administration," John Swenson-Wright, an expert on North Korea at the London-based Chatham House think tank, wrote in an e-mail response to questions.

Some analysts don't hold out much hope for accurately measuring North Korea's capabilities until they are demonstrated verifiably.

Dujarric, for instance, said that in the absence of outside inspections, conclusive proof that Pyongyang has a nuclear weapon can only come when the regime explodes one.

"If you want to know if they have a functioning nuclear device that can be put on a missile, which is the real question, you'll know it when they fire a missile and there's a mushroom cloud wherever it lands," he said.