In an increasingly interdependent world, the forms of intervention involve a spectrum of actions from radio broadcasts through spying by satellite to economic embargoes and military intervention. Given both the history of intervention and the conditions that facilitate it today, the fact that intervention is continuing is not surprising.
What is noteworthy, however, is the call from several quarters to change the norms governing intervention, to expand the justification for intervention, including even military intervention. The call to do this is not a unanimous opinion by any means, but it is a substantial voice. The pressure for change arises from two sources: the internal conditions within countries and the erosion of restraints on intervention at the international level.
Internal atrocities of "ethnic cleansing" revive the memory of genocide; the appalling mass starvation in Somalia assaults even the most hardened conceptions of what is tolerable in human affairs. Yet the growing propensity toward intervention, in my view, is due less to the nature of the atrocities than to the loosening of the restraints on intervention.
During the Cold War, there were two barriers to intervention -- one rooted in principle, the other in prudence. The prudential restraint was the fear on the part of both superpowers (and the other major powers) that intervention in a third country could draw them into a wider conflict with the ultimate threat always being a nuclear engagement. At the level of principle, the norms of international law uphold a standard of absolute non-intervention. The norm has never been entirely obeyed (particularly by the superpowers, as Vietnam, Czechoslovakia, the Dominican Republic, and Afghanistan testify), but it was neither denied in principle nor denigrated by states.