FROM SYNC: History as melodrama. This exciting production, recorded before a live audience, dramatizes the WASHINGTON POST's struggle with the Nixon administration over the publication of the Pentagon Papers. Much of the dialogue is lifted straight from the historical record. Whether or not this is accurate history, it certainly makes excellent theater, reminiscent of the agitprop (agitation/propaganda) and Living Newspaper plays of the Depression. John Rubenstein has directed his fine ensemble to play broadly and to maintain that thrill of immediacy that surely informed the actions of the actual participants. Present, too, is the humor, intentional and otherwise, that forms an important part of the story, none of it lost on a sharp and enthusiastic house. A riveting subject is given its due. Y.R.