Soman gas (GD) is a real nerve agent, it is related to the more commonly known (and far more deadly) nerve agent sarin (GB). Both soman and sarin are organophosphate neurotoxins, they are classified as both chemical weapons and weapons of mass destruction by the United Nations. Production of agents like soman and sarin are strictly regulated and controlled, and stockpiling of either agent was outlawed by the Chemical Weapons Convention of 1993; production of sarin for any reason was outlawed by an addition to the UN ban in 1997, only very limited quantities of other related nerve agents like soman can be produced and only for the purpose of medical research to find more effective antidotes and treatments. Organophosphate nerve agents like soman and sarin work by inhibiting the enzyme cholinesterase, which is used to produce an enzyme (acetylcholinesterase) that degrades the neurotransmitter acetylcholine. Acetylcholine is the neurotransmitter the nervous system uses to cause muscles to contract, acetylcholine activates motor neurons causing the muscle to contract and acetylcholinesterase then strips the acetylcholine away from the nerve receptor causing the muscle to relax. Without the ability to produce acetylcholinesterase all of the body's muscles cannot relax after being contracted, leading to death by asphyxiation due to the muscles in the diaphragm no longer functioning. Symptoms of soman and sarin exposure are very similar: constricted pupils, drooling, nausea, vomiting, muscle spasms, trouble concentrating, pain in the extremities, loss of control over bladder and bowels; as death nears the person starts twitching and jerking (sometimes violently), until they become comatose and suffocate while spasming. Sarin is one of the most toxic substances known, it is almost three times as toxic as soman and 26 times as cyanide. The main treatment for organophosphate exposure is atropine, prompt treatment is essential even if exposed to minute amounts, doses as small as 1% of the lethal dose can cause permanent nerve damage. People exposed to these agents that are successfully treated, even when exposed to small doses, can have permanent neurological damage as well, they have been known to suffer from depression, antisocial personality disorder, insomnia, night terrors and suicidal thoughts for years afterwards.
Palmer says that if he didn't care about collateral damage he would just fire a Dragon into JAG headquarters and be done with it. He is likely referring to the M47 Dragon, a man-portable, shoulder-fired anti-tank guided missile system. Developed during the Cold War in 1975 to defeat Soviet tanks the Dragon fires a wire-guided, high-explosive armor piercing warhead capable of defeating armored vehicles, fortified bunkers, main battle tanks, and other hardened targets. The US retired the Dragon in 2001 and replaced it with the FGM-148 Javelin Advanced Anti-Tank Weapon System, the Javelin's main advantage is its missile is self-guided via infrared homing and does not need to be attached with a wire. It is a fire-and-forget weapon and allows the user to take cover immediately after firing, unlike fly-by wire missiles which required the user to remain standing and aiming at the target until the missile struck it.
Lt. Colonel Vickers and the scandal regarding him selling chemical weapons to Libya is loosely based on Lt. Colonel Oliver North and his involvement in the Iran-Contra scandal in the mid-1980's. Colonel North was accused of selling weapons to members of the Taliban in Iran, to be used against the Soviets, and using the money from those weapon sales to finance a rebel faction fighting to overthrow the communist government of Nicaragua, in direct violation of US law. North claimed he was acting under orders and that it was a sanctioned operation, but when word of it leaked to the media North quickly became the scape-goat with Washington placing the blame solely upon North in order to save their own asses. Colonel North was court-martialed for disobeying a direct order, violating US weapons laws and treason but was ultimately acquitted on all charges. He was not able to prove that he was acting under orders but there was enough evidence to create reasonable doubt as to the fact that he was acting alone, as it would be next to impossible for a Lieutenant Colonel to move the amount of weapons in question without at least several Colonels and Generals above him in the chain of command knowing about it. In fact Oliver North himself made a few cameos in season one, he appeared in Desert Son (1995) & Hemlock (1996) as himself and was an old friend of Lt. JG Austin's father; he also makes one last appearance in the season eight episode Ready or Not (2002).