Initial talks between the State Department and North Korea over the fate of Army pilot Bobby Hall have failed, prompting President Clinton to angrily demand Hall's release. "There is no reason for his detention," Clinton told reporters, adding that he'd not comment further until talks are completed. Clinton's remarks came the same day the North Koreans released what they called Hall's confession in which Hall is quoted as saying that his helicopter "illegally" intruded "deep into the territorial airspace" of North Korea. Meanwhile, Thomas Hubbard, a deputy assistant secretary of state, traveled to North Korea yesterday but, according to Rep. Lee Hamilton, outgoing chairman of the House Foreign Relations Committee, the talks "were not very satisfactory." The snag? Persuading North Koreans that Hall wasn't on a spy mission as they claim. Now that Hubbard has failed, U.S. military officials are now take on the task. While President Clinton stopped short of saying the U.S. - North Korea nThe standoff with the North Koreans sparked speculation yesterday that an internal power struggle was under way between the Pyongyang's military -- favoring a tough stance against the U.S. -- and more moderate diplomats. But Waller says Administration intelligence officials are "quite skeptical of that theory. They think this may be the way North Koreans deal with the outside world -- with Seoul and with the United States."