Rasmussen had spent much of the past five years preparing for just such an event as this.

In 2000 and 2004, he had organized a series of exercises called "Strong Angel," designed specifically to address ways the U.S. military could better assist emergency humanitarian relief efforts in disasters worldwide. The second set took place on a bed of crushed lava in Hawaii meant to simulate the austere conditions that might be found in the Iraqi desert—or in the aftermath of a natural disaster.

The collaboration between military, academic and international relief organizations drew on diverse strains of influence, such as the Burning Man Festival, an annual arts gathering that coordinated itself through a high-speed wireless network in Nevada's Black Rock Desert, and the ready availability of "cheap and cheerful" technologies such as "cantennas," which could put a powerful directional antenna in anyone's hand for less than $50.

Rasmussen and colleagues inside and outside the military had been promoting the idea that the restoration of roads, bridges, ports, water, sanitation and other basic human needs could be planned for, practiced on and responded to quickly through the smart use of such cheap technology.

But here in Aceh, in a real crisis, Rasmussen saw relief efforts rendered inefficient by a lack of basic information— where the water, medicine, wood and other supplies were needed most, and how to get them there.

The scope of this series of tidal waves made the response particularly challenging.

Only a few other calamities—a 1970 cyclone in Bangladesh, a 1976 earthquake in China, and the famine in Ethiopia in 1984 and 1985—had cost more lives. The rush to offer assistance only complicated communications and coordination. More than 100 relief agencies, including CARE and the International Medical Corps, converged on the disaster area. Combined with military hospital units from many nations and an assortment of U.N. agencies, coherent management of the overall operation would prove close to impossible.

Observing along with Rasmussen and trying to suggest ways to make the mission work better were Dave Warner, a collaborator on Strong Angel and other projects, and Dan Engle, a retired Navy networks architect and independent consultant.

When not on a humanitarian mission, Rasmussen is a full-time doctor at a Navy hospital in Bremerton, Wash. But he also manages projects for the Defense Advanced Research Projects Agency (DARPA) and the Center for Robot Assisted Search and Rescue, which sent mechanical searchers into the ruins of the World Trade Center. He has taught medicine at the U.N. Office of the Coordination for Humanitarian Affairs in Geneva, and lectured on how to examine torture victims. The U.S. Agency for International Development (USAID) has him on the short list of people it calls to coordinate the humanitarian response to disasters around the world.

All of these roles—military man, doctor, humanitarian and technologist—surfaced in the Strong Angel exercises. In particular, the second set, held last July in Kona, Hawaii, emphasized technologies that could support electronic collaboration either on a battlefield or in a disaster zone. One ground rule: Participants had to rely solely on satellite and wireless communications gear they could carry.

The system they pieced together during the weeklong exercise included a Web site and a system of synchronizing folders—a "collaborative workspace" known as a Groove network—that could have sped up road clearing and the delivery of fresh water in Banda Aceh. That much was clear to Nigel Snoad, chief information officer of the U.N. Joint Logistics Centre (UNJLC) and a Strong Angel II participant.

Summoned back from vacation, Snoad had arrived in Indonesia on Dec. 28. He acted as a logistics coordinator, fielding calls asking basic questions like how to get a plane into Banda Aceh, how to get a car, and which roads were open.

At one point on Jan. 2, he shut off his cell phone for a half-hour to talk to a relief worker. When he switched it back on, he found 58 voice mails waiting. "It was driving me insane," he says.

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