Like a live hand grenade brought home from a distant battlefield, the 34-year-old antiwar documentary "Winter Soldier" has been handled for decades as if it could explode at any moment. Now, the 95-minute film - which has circulated like 16-millimeter samizdat on college campuses for decades but has never been accessible to a wide audience - is about to get its first significant theatrical release in the United States, beginning on Friday at the Film Society of Lincoln Center. David M. Halbfinger >reports in the New York Times (free subscription required to view).