If the vice president and the FBI director are correct, more terrorist strikes against America are inevitable. What happens then?

For a nation unaccustomed to mass carnage on its soil, Sept. 11 was more than mere shock. It was virtually inconceivable.

A future large-scale attack may not be so surprising. Indeed, with Vice President Dick Cheney and FBI Director Robert Mueller warning that not all attacks will be stopped, public agencies and private citizens are pondering worst-case questions. Next time, how will Americans react psychologically? How should families of victims be compensated? Are emergency services up to the challenge?

Many jurisdictions – including big cities like New York – have not issued detailed advisories to their residents, saying there are too many variables. But New York’s Police Department is considering new procedures for responding to any future attack, such as creating a “shadow staff” to run the department if top commanders are killed.

Authorities in Maryland, Virginia and the District of Columbia have been working to coordinate their responses – including evacuation plans – in the event of a terrorist strike on Washington. At the Lawrence Livermore National Laboratory in California, scientists are developing a plan to track toxic agents in the event of a biological or chemical attack.

Fire departments and emergency workers in many communities have been practicing decontamination drills. Even the Humane Society of the United States is acknowledging the terrorist threat, urging families with pets to account for the animal when they develop evacuation plans.

The American Red Cross has overhauled both its fund-raising policies and preparedness efforts.

Training has been expanded at the Clara Barton Center for Domestic Preparedness, on the grounds of the Pine Bluff Arsenal in Arkansas. The goal is to prepare Red Cross volunteers to respond to biological, chemical or nuclear terrorism.

“These incidents tend to be very complex,” said Armond Mascelli, the Red Cross senior director of disaster services. “You do your best to puzzle through it, and look at the contingencies. But even with the best of planning, issues will come up that weren’t anticipated.”

The Red Cross also has acted to avoid a recurrence of criticism that surfaced after Sept. 11, when many donors grumbled at revelations their gifts would be used in response to future disasters.

Under a new program implemented July 31, donors are urged to give unrestricted gifts to a relief fund that could be tapped in response to any number of different disasters.

Relief experts say the planning challenges they now face are unprecedented.

“In preparing for disasters in the past, we were always able to map vulnerabilities and risks – we knew coastal states were more vulnerable to hurricanes, the Midwest to flooding,” said Rick Augsburger, an emergency-response coordinator with Church World Service.

“With terrorism, the entire country is impacted and traumatized.”

Augsburger also noted that responses to past disasters focused on meeting material needs.

“September 11 brought a shift – realizing the importance of supporting people spiritually and emotionally,” he said. His agency is studying ways to reduce burnout and “compassion fatigue” among clergy ministering to traumatized people after a future attack.

Psychologists and terrorism experts offer varying predictions of how Americans will react emotionally to another strike.

Gerard Jacobs, director of the Disaster Mental Health Institute at the University of South Dakota, is concerned Islamic Americans might suffer more harassment. But overall, he said, “the American people tend to pull together more than they tend to pull apart.”

One sensitive matter almost certainly will be handled differently after future attacks – compensation of victims’ families.

The Bush administration is proposing that future terrorism compensation awards be capped at $250,000, which is far lower than the estimated average payment of $1.85 million expected to be awarded to Sept. 11 families from the federal Victim Compensation Fund.

Families accepting awards from the fund had to waive their right to sue, but the Bush administration proposal would not impose that restriction in future cases.

As for the American people, Red Cross fund-raising executive Michael Farley believes the outpouring of support seen after Sept. 11 would be repeated in response to a future attack.

“I see a bottomless well of generosity,” he said. “One of the characteristics of Americans is the willingness to support one another, no matter what the frequency or gravity of the disaster.”