SEOUL — North Korea's previous nuclear test and missile launches had a ring of foot-stamping about them, certainly a modest security threat, but also a demand that Washington pay the nation some attention.
This time, its motives seem more complex, the international bravado blended with the mysteries of the secretive regime's internal politics. Instead of tweaking the United States, the latest nuclear test may have been aimed at shoring up an ailing Kim Jong Il's support from the country's military establishment, many analysts said, perhaps to ensure that power remains within the Kim family.
Since reportedly suffering a debilitating stroke last year, Kim has been seeking a smooth handoff of power -- presumably to the youngest of his three sons -- and would like to settle the country's long-running clash with Washington before that leadership shift takes place.
"Because of his declining health, Kim now feels he must be on a faster timetable," said Moon Hong-sik, a research fellow at the Institute for National Security Strategy in Seoul. "The U.S. has ignored him. He feels the pressure and he's upping the odds."
The nuclear test is the latest sign of a more assertive North Korean foreign policy. The North has escalated tensions with South Korea in recent months, abrogating some trade deals and professing to be preparing for war. And Monday's underground explosion comes weeks after a rocket launch in April that Pyongyang claimed placed a communications satellite into orbit, but which most independent observers said was a disguised long-range missile test.
The satellite, if there was one, did not reach outer space, analysts say, and the U.S., South Korea and Japan nonetheless sought new United Nations sanctions.
Monday's nuclear test was accompanied by the test-firing of a short-range missile, and possibly two more, according to unnamed South Korean officials. The news spawned protests in Seoul, where scores of activists marched brandishing a model of a nuclear weapon papered with pictures of Kim to protest the North's move.
Analysts speculate that Kim is providing a fireworks show to secure the approval of his military generals.
"Since the appearance of health issues with Kim Jong Il last year, the North Korean military became more influential," said Cheong Seong-chang, director of Inter-Korean Relations Studies Program at Sejong Institute near Seoul.
