America must not "dictate" to world, new defense chief says 2:01pm EST By Phil Stewart WASHINGTON (Reuters) - Decorated Vietnam veteran Chuck Hagel was sworn in as U.S. defense secretary on Wednesday after a bruising Senate confirmation battle, and promised to renew old U.S. alliances and forge new ones without attempting to "dictate" to the world. Addressing Pentagon employees shortly after a small, closed-door swearing-in ceremony, Hagel spoke optimistically, if vaguely, about global challenges ahead and the importance of American leadership abroad. "We can't dictate to the world. But we must engage the world. We must lead with our allies,"...