The strike, as envisioned, would be limited in the number of targets and done within a day or two. It could be completed in one fell swoop with missiles, said one senior official familiar with the weapons involved. A smaller, follow-on strike could be launched if targets aren’t sufficiently damaged.

A second senior official, who has seen the most recent planning, offered this metaphor to describe such a strike: If Assad is eating Cheerios, we’re going to take away his spoon and give him a fork. Will that degrade his ability to eat Cheerios? Yes. Will it deter him? Maybe. But he’ll still be able to eat Cheerios.

The two officers with current and recent service in the Middle East say the term “degrade” is so vague that it could be used to describe the effect of a single cruise missile strike.