Meanwhile, the Syrian rebels are exasperated and mistrustful, having seen Washington dangle the prospect of U.S. military strikes, only to back away. The Iranians are drawing comforting lessons about the lengths that the Obama administration will go to avoid military action in the Middle East. The Russians have been promoted from reprehensible accomplices in Assad’s evil to indispensable peace negotiators—while they remain accomplices to that evil.

What lesson will dictators around the world derive from all this? They will see that there is enormous utility in creating a chemical-weapons arsenal, and even in using such weapons. Sarin gas, VX, anthrax and the like can be valuable for intimidating one’s enemies, foreign and domestic, and for killing them. They can then be traded away at a very high price under the right circumstances. They can serve as a lifesaver for a dictator on the skids.

Clever dictators will realize that they can barter their chemical-weapons arsenals to buy time to crush an insurrection and then rebuild the arsenal after the population has been pacified.