A diffuse, elaborate essay on the submerged ideological context of Watergate, centering on that tendentious cliche ""credibility."" In the evolving post-Cold War strategy, nuclear weapons--useless as a flexible instrument of policy--were to be supplemented by limited war capabilities. Any situation which offered a pretext for symbolically affirming the national will was a test of ""credibility"" military strategy after Dulles became PR strategy. The ""illusion"" of the title is not merely the duplicities of the Nixon crew; it encompasses all the bizarre posturings that our own inconceivable weapons have thrust on us. In Schell's view the special achievement of Nixon and his cohorts (particularly Buchanan and such jerry-built instruments as the President's Advisory Council on Executive Reorganization) was to have eliminated even the pretense that realities generate images, and to have made the reverse process a tool of conscious policy--courting legis. lative failure, for example, in order to juggle congressional ""scenarios."" ""The President's fantasy was father to the fact""; in the dream world that he almost managed to foist on us, he ""was becoming the author of his own environment. He manufactured events and then he 'responded' to them."" Domestic opponents, who posed a more volatile threat than foreign adversaries to the image of authoritative presidential will, inevitably became the real ""enemies."" This wide-ranging thesis, presented with reams of exasperating past-perfect backtrackings over backtrackings, is nonetheless consistently and appallingly convincing. More than any of the brash psychohistorical studies of presidents we've been treated to in recent years, this discreet and distanced analysis makes clear the kinship of major national policies, over more than half a decade, with the thought processes of true psychosis. First serialized in The New Yorker.