Chemical weapons are extremely lethal, easy to produce, and can be produced quickly. That's why many wars and assassinations use them. Organophosphate nerve agent is the most famous among chemical weapons. The reason why  organophosphate nerve agent is lethal is because of its mechanism. First, organophosphate compounds lead to acetylcholinesterase block. Second, Acetylcholine overstimulates synaptic receptors by accumulating at synapses. Finally, organophosphate nerve agent cause living creatures’ death of respiratory depression. Owing to its mechanism, it only takes low dose to be lethal. Therefore, organophosphate nerve agent is easy to produce and can be produced quickly. Based on the above characteristics, organophosphate nerve agent is used widely in many wars and assassinations.