The opening days of a war with Iraq would likely see weapons and tactics straight out of Buck Rogers. Cruise missiles, pilotless drones, and "blackout bombs" spitting out spools of carbon filaments to short out power lines. Powerful electromagnetic pulses - "E-bombs" - frying computer and communication circuitry. High-power microwave weapons.
The point is to hamper the ability of Iraq to fight back by shutting down critical electronic systems, especially those in hardened underground bunkers. They might also help if Saddam Hussein has hidden biological or chemical weapons, since those could be damaged if refrigeration units fail.
A war with Iraq, in fact, may prove the biggest test to date of the effectiveness of many of the US military's fancy new weapons. For the first time since the Panama invasion in 1989, the US may be fighting a largely urban war. Thus the tactics and technology it uses will be crucial in determining the level of casualties and perhaps the length of the war itself.
One possible genre of weapons that could be used, for instance, is riot-control agents - nonlethal chemicals such as tear gas and pepper spray - to flush out enemy fighters or put down POW revolts.
US military officials won't say much about any of this. "There certainly exists the possibility for the use of nonlethal weaponry under certain circumstances," Army General Tommy Franks, commander of all US forces in the Persian Gulf region, said recently. "One example would be offensive electronics."
But, he added, "The specifics of those circumstances wouldn't be something that we would want to talk about in public."
Others have been talking about the advantages and dangers of such weapons for decades, and their development has been going on for nearly as long. Some have already been tested in combat.
"In Kosovo, unlike the first Gulf War, instead of bombing electricity generating plants, we dropped carbon filaments that short-circuited the plants for 4-6 hours," says Army Col. Dan Smith (USA, ret.). "That's the good news. The bad news is that unless the filaments are collected when they finally fall to the ground, winds can pick them up and throw them back into the wires, recreating short-circuits."
Other experts caution that such weapons can in fact be deadly. "It should be noted that nonlethality is an aspiration rather than an assured outcome," says Loren Thompson of the Lexington Institute in Arlington, Va., who has recently completed a study of directed-energy weapons. "Some people may be killed by the direct or indirect effects of 'nonlethal' weapons."
Most controversial would be the use of chemicals designed to defeat enemy soldiers without killing them - particularly in what is called Military Operations on Urbanized Terrain, where innocent civilians could be caught in the crossfire or used as human shields.
The international Chemical Weapons Convention allows police forces, but not military units, to use such weapons. But military use in situations more akin to law enforcement is a gray area under international law, US officials say, and tear gas was used against hostile Serb crowds in Bosnia. Marine Corps units in the Gulf area reportedly have tear gas and pepper spray in their arsenal.
"The question is whether we stick to the ban and kill people, or use them as a method to save lives," says Army Col. John Alexander (USA, ret.), former head of nonlethal defense programs at the Los Alamos National Laboratory. This is essentially the argument made by Defense Secretary Donald Rumsfeld in recent congressional testimony.
Other experts strongly disagree. "The Chemical Weapons Convention ... explicitly prohibits the use of riot-control agents in warfare," says Barbara Hatch Rosenberg, a molecular biologist at the State University of New York who chairs the Federation of American Scientists' working group on biological and chemical weapons.
"The US has a history of using nonlethal weapons to increase the lethality of other weapons," says Dr. Rosenberg. "Tear gas was extensively used in Vietnam to flush out hidden troops to they could be shot."
Even if that doesn't happen in Iraq, one of the many unknowns that Secretary Rumsfeld frequently harps on is the length, ferocity, and possibility of collateral damage (including civilian casualties) in the urban ground war - even if so-called nonlethal weapons are a key element.
"I don't think we have anything that will make the urban fight radically easier," says military analyst Michael O'Hanlon of the Brookings Institution in Washington.
Whether nonlethal military hardware amounts to "weapons of mass protection," as some boosters assert, or a potentially dangerous step into a new and murky world of warfighting remains to be seen.
"I suspect future scholars will see the concept of nonlethal warfare as closely tied to the digitization of combat," says Dr. Thompson. "As military forces become more and more dependent upon electronic sensors, computers, communications and navigation devices for battlefield success, the possibility of victory through denial of access to the electromagnetic spectrum is increasingly appealing."
Since much of the technology here is widely available, it's also possible that the US itself might have to counter communications jamming, computer viruses, and microwave pulses at some point.
"This may be a more humane and discriminate way of waging war," Thompson adds. "But it also creates new vulnerabilities that US planners have barely begun to consider.