By MICHAEL IGNATIEFF The New York Times

"CHAIN OF COMMAND'' is the best book we are likely to have, this close to events, about why the United States went from leading an international coalition, united in horror at the attacks of 9/11, to fighting alone in Iraq and, in Abu Ghraib, to violating the very human rights it said it had come to restore. According to Seymour M. Hersh, whose revelations this spring about the Abu Ghraib scandal have matched in impact his breaking of the My Lai story in 1969, this fatal declension was a direct consequence of presidential decisions taken long before combat in Iraq. The war on terror began as a defense of international law, giving America allies and friends. We now have two major accounts of the road to war in Iraq, Hersh's ''Chain of Command'' and Bob Woodward's ''Plan of Attack.'' Hersh is the anti-Woodward. Woodward is official scribe to the inner sanctum, and his access -- to Bush, Cheney, Rumsfeld and Powell -- gives his account real authority, but at a price. In Woodward's world, everything is what the principals say it is. In Hersh's world, by contrast, nothing the policy elites say is true actually is. Sy Hersh would be persona non grata in that inner sanctum, because unlike Woodward, he is not inclined to take dictation from presidents. Read on