TOKYO — North Korea took a step on Thursday toward reintegration into the world community and rapprochement with the United States by submitting for outside inspection a long-delayed declaration of its nuclear program. The 60-page declaration from North Korea, one of the world’s most isolated and impoverished nations, was expected to describe in previously undisclosed detail its capabilities in nuclear power and nuclear weapons — meeting a major demand of the United States and other countries that consider the North a dangerous source of instability. “This can be a moment of opportunity for North Korea,” said President Bush, announcing the...