Some twenty countries have CW programs. This is one of the gravest, mounting dangers of our time. The second reality is that chemical weapons today are legal. The 1925 Geneva Protocol amounts to a ban only on first use, and only in international conflict. It did not, for example, cover Iraq's use of chemical weapons against its own people.
States harboring terrorists can legally hand out chemical agents.
We can know about the biggest underground chemical weapons facility in the world, Libya's Tarhunah complex. But there's no legal basis for sanctions or other action, because it's not against the law. So keep in mind that the alternative to the CWC is to give rogue states and terrorists a free pass to have chemical weapons. That would be particularly perverse in light of the third reality, which is that this treaty is about other countries' weapons, not ours. In 1985 President Reagan signed a law mandating destruction of our stockpiles.