NATIONS used to think twice about meddling with their neighbors' internal affairs. Complaining that someone else's election was corrupt or the populace was mistreated was contrary to some unwritten code of conduct - equivalent to telling the guy next door that he was raising his kids wrong.
For the United States the cold war only intensified this attitude. Forcible intervention seemed too dangerous, as it might lead to superpower confrontation. Exceptions were undertaken only for what were thought to be gravely important reasons.
But in the post-cold-war era, national sovereignty has perhaps lost its mystique. What political scientists call ``the norm of nonintervention'' seems to have been greatly weakened, with nations and citizens increasingly viewing morality as something more important than borders. ``The international community, acting as a community, has become more willing to sanction intervention into troubled countries,'' says Michael Mandelbaum, professor of US foreign policy at the Johns Hopkins School of Advanced International Studies in Washington.
Hence the effort to rebuild Somalia, which still goes on despite the exit of most US troops. France has gone into Rwanda with a self-described similar humanitarian intention. UN peacekeeping efforts in general have multiplied, with more such operations approved since 1989 than occured during the entire period of 1945-1988.
This intervention trend actually began in the 1960s and '70s, Mr. Mandelbaum says, with the UN censuring the white governments of South Africa and Rhodesia for oppression of their black majorities. It accelerated when the fall of the Soviet Union eliminated fear of a superpower confrontation.
But while the world looks on intervention more approvingly in theory, in practice it is increasingly difficult for key nations to muster public support for bearing intervention costs.
Forcibly attempting to improve another society can be a long and costly experience. The US public largely accepted that there were strategic stakes in the cold war standoff. Sympathy - for starving Somalis or endangered Haitians - has so far proved a problematic motivational tool.
Haiti has been a good example of this dynamic. While the world may agree that the Haitian junta grossly abuses its citizens, few nations want to join the US in a possible military action. Strong US opposition to an invasion of Haiti has already surfaced, both among Republicans and some congressional Democrats.
The Clinton administration has tried to describe a possible invasion as something more than a humanitarian move, since US interests are at stake in halting the flood of Haitian refugees. Critics worry that President Clinton will be tempted to intervene with force in Haiti to establish his foreign policy toughness and boost domestic popularity.
But the rally-round-the-flag effect that occurs when a president uses US troops raises his ratings only 7 percent on average, according to a study by the Massachusetts Institute of Technology. And the boost is short-lived at best. ``While Americans may be willing to intervene on behalf of clear victims of aggression, policymakers should be aware that the public is not eager to save a country from itself,'' writes David Burbach, who studied dozens of post-war ``rally'' incidents.