San Francisco ? Army Maj. Gen. David Grange is proud to have ordered his troops to use tear gas on hostile Serb crowds in Bosnia six years ago.

“We didn’t kill anyone,” said the now-retired Grange. “It saved lives.”

His only complaint was that red tape prevented him from using tear gas more often.

The Pentagon is drafting guidelines under which American soldiers could use riot control agents such as tear gas and pepper spray in Iraq to control unruly prisoners and separate enemy soldiers from civilians, Defense Secretary Donald H. Rumsfeld told Congress earlier this month.

Problem is, soldiers who use so-called “nonlethal agents” in combat outside their own countries are violating the very chemical weapons treaties the United States accuses Saddam Hussein of flouting.

“We are doing our best to live within the straitjacket that has been imposed on us on this subject,” Rumsfeld said on Feb. 5. “We are trying to find ways that nonlethal agents could be used within the law.”

Legal issues notwithstanding, the Pentagon has also explored developing other, far more exotic and powerful chemical agents that could be used in conflicts.

No riot-control agents

While countries may use nonlethal chemicals domestically for law enforcement and crowd control, the Chemical Weapons Convention that took force in 1997 and has been ratified by 149 countries including the United States, specifies: “Each state party undertakes not to use riot-control agents as a method of warfare.”

That provision was hotly contested during the 15 years it took to craft the treaty. It arose as an objection to the United States’ reliance on tear gas to flush out Viet Cong fighters and kill them during the Vietnam War.

The convention does allow, however, for riot control agents to be used for “law enforcement.” Whether “law enforcement” extends beyond a nation’s borders is a matter of fierce international debate. The concept will be discussed in April when the treaty comes up for international review in The Hague, Netherlands.

Weapons-control activists cite myriad reasons for banning nonlethal chemical weapons in war.

The agents can actually kill, they argue, when used in war environments. They could also put militaries on a slippery slope to using nastier, deadlier chemicals.

Beyond irritants

Irritants such as tear gas and pepper spray are tame in comparison to other agents under development.

The U.S. military has explored mind-altering drugs such as opiates, along with genetically engineered micro-organisms that can destroy objects like runways, vehicles and buildings.

The research is spearheaded by the U.S. Marine Corps’ Joint Non-Lethal Weapons Directorate, which was created in 1997 to equip soldiers on overseas peacekeeping and other noncombat duties.

The directorate’s mission is to help troops deal with panic-stricken or hostile crowds, like those faced in a failed peacekeeping mission in Somalia.

In one 1993 street battle in Mogadishu, 19 U.S. soldiers and more than 1,000 Somalis were killed. Some military experts say the death toll would have been far lower had soldiers fired nonlethal chemical weapons.

A Pennsylvania State University institute prepared a 50-page report with Pentagon funding in October 2000 that explored a range of drugs — including Prozac, Valium and Zoloft — for use as “calmatives” for crowds.

The researchers found “use of nonlethal calmative techniques is achievable and desirable.”

Despite the endorsement, Marine Capt. Shawn Turner of the nonlethal weapons directorate said the military stopped “calmative” research because such drug-weapons may violate international law.

Turner said much of the directorate’s $25 million annual budget is spent developing “directed energy” weapons such as laser or microwave guns that stun rather than kill.

“With all these technologies starting to surface in security and the military, maybe there is a real need to revisit these international conventions to reassess if they are still applicable,” said Andrew Mazzara, director of the Penn State institute that prepared the calmative report.