Wright noted that the first signs the outside world got of North Korea's long-range Taepodong-2 missile — upon which the recent failed rocket was based — was from mock-ups seen in 1994, 12 years before it was actually tested on the launch pad.
"To understand whether there is a real missile development program in place, we are trying to understand whether the mock-ups make sense as the design for a real missile," he said. "It is not clear that it has a long enough range to make sense for North Korea to invest a lot of effort in."
Theodore Postol, a professor at the Massachusetts Institute of Technology and former scientific adviser to the U.S. Chief of Naval Operations, said the Taepodong-2 design remains the more real future threat — though even that remains at least a decade away — and the KN-08 is simply a smoke screen.
"I believe that these missiles are not only mock-ups, but they are very unlikely to be actual mock-ups of any missiles in design," he said. "Fabricating a missile like the KN-08 would require a gigantic indigenous technical effort. ... The only way North Korea could develop such a missile with its pitiful economy would be if someone gave it to them."
He noted that a comparable U.S. missile, the Minuteman III, required "decades of expertise in rocket motors, and vast sums of intellectual, technological and financial capital."
Much attention, meanwhile, has been given to the 16-wheel mobile launchers that carried the missiles during the parade, which experts believe may have included a chassis built in China. That raises questions of whether China has violated U.N. sanctions against selling missile-related technology to Pyongyang.
Some missile experts say the launchers were designed to carry a larger missile than the 18-meter-long KN-08, and argue that North Korea would not have spent millions of dollars on them unless it has, or intends to have, a big missile to put on them.
But Wright said the launchers, like the missiles they carried, could also have been more for show than anything else.
"Given the international attention it has gotten from parading these missiles you could argue that the cost of buying the large trucks — which add a lot of credibility to the images of the missiles — was money well spent in terms of projecting an image of power," he said.