WATERLOO, Ontario — The 1990s was a decade of conscience-shocking atrocities in Rwanda, the Balkans and East Timor. Unilateral actions by India and Vietnam to end atrocities in the 1970s had drawn international opprobrium and condemnation. The crises of the 1990s provoked agonized soul-searching on how to reconcile a newly energized international conscience with clashing principles of world order that privileged sovereignty over intervention.