That was not the case in the simulation, sponsored by the military’s Joint Forces Command. The victory of the force modeled after a Persian Gulf state  a composite of Iran and Iraq  astounded sponsors of what was then the largest joint war-fighting exercise ever held, involving 13,500 military members and civilians battling in nine live exercise ranges in the United States, and double that many computer simulations to replicate a number of different battles.

General Van Riper’s attack was much more complex and sophisticated than anything that could have involved the Iranian boats last weekend. The broad outline of the 2002 war game was reported at the time, but in interviews since last weekend’s episode, General Van Riper and other officers have provided new details about the simulation.

In the war game, scores of adversary speedboats and larger naval vessels had been shadowing and hectoring the Blue Team fleet for days. The Blue Team defenses also faced cruise missiles fired simultaneously from land and from warplanes, as well as the swarm of speedboats firing heavy machine guns and rockets  and pulling alongside to detonate explosives on board.

When the Red Team sank much of the Blue navy despite the Blue navy’s firing of guns and missiles, it illustrated a cheap way to beat a very expensive fleet. After the Blue force was sunk, the game was ordered to begin again, with the Blue Team eventually declared the victor.

In a telephone interview, General Van Riper recalled that his idea of a swarming attack grew from Marine Corps studies of the natural world, where insects and animals  from tiny ant colonies to wolf packs  move in groups to overwhelm larger prey.

“It is not a matter of size or of individual capability, but whether you have the numbers and come from multiple directions in a short period of time,” he said.

Although Washington and Tehran continue to duel over details of the encounter, American officials say the Iranians may have been seeking to provoke a violent confrontation as President Bush was about to visit the region. Or, the officials say, they might have been hoping to test the American reaction. Yet there is no certainty that the encounter was ordered by the government in Tehran.