''That sympathy will disappear very quickly the moment we take innocent lives,'' said Han Park of the university's Center for the Study of Global Issues.

U.S. military action could begin a much bigger war, Mr. Park warned.

''The most dreaded outcome,'' he said, would be a large-scale religious conflict between Muslims on one side and Christians and Jews on the other that ''would be catastrophic.''

Mr. Park spoke at a university-sponsored seminar with six other faculty members Monday in the university chapel. They called it Aftershock: Coming to Grips with Terrorism in America.

Europe could quickly be dragged into the war, said Carlo Pelanda, a visiting faculty member who is a consultant to the Italian Ministry of Defense. His job is envisioning global scenarios, and this one could be a nightmare, Mr. Pelanda said.

One alternative to war is to hunt down those responsible for the attacks, but the United States has not been very effective at that - British commandos are better, he said. But the war scenario?

''For us this is hell, because we are on the front line,'' Mr. Pelanda said, noting the vital importance of Middle Eastern oil to European countries.

The more American-led military action, ''the more Italy, Britain, France and Spain would be exposed to a bigger act of war,'' he said.

Any country now has access to weapons of mass destruction, and the way big countries have imposed order on the world for the past 2,000 years - military and political domination - just won't work any more, Mr. Park said.

At the same time, all around the world, ''nationalism, even super-nationalism, is on the rise. Fanatic believers are on the move all across the world,'' said Mr. Park, who painted a bleak picture of the outcomes that might arise from the Sept. 11 attacks and the U.S. response.

''The stark reality is that the world is diverse now. Small powers do not act like small, subservient states any more. In a way, there is no global world order,'' Mr. Park said.

The United States is still respected, even revered, around the world, but that is changing, Mr. Park said.

''There is a growing anti-American sentiment around the world,'' he said.