The name Bernardo Bertolucci may bring to mind the hot buttered love of Last Tango in Paris. But that wasn't the Italian director's most rebellious creation. Now on DVD in its full five hours, 1900 follows two childhood buddies. Alfredo, played by an unsettlingly timid Robert De Niro (Bertolucci cast him because he was ''a kind of delicate figure''), is the heir of a wealthy landowner; Olmo (Gérard Depardieu) is a proletarian who rebels against the gentry. The frank sexuality still startles, along with some horrifying violence, but 1900's edge is political. Bertolucci says in a making-of that he intended to create ''a bridge'' between the U.S. and the Soviet Union. In fact, the film was ''hardly shown'' in either, he says, because there were ''too many red flags.'' Literally. Bertolucci chopped an hour for the U.S. theatrical release. But if the virtuosic filmmaking and usual saga fare class struggle, fatherless sons, weddings, war, and funerals aren't enough to hold your attention, Donald Sutherland as an evil fascist is.