Well maybe he didn’t make a mistake. I see in the OP that it’s an attack against a country that killed some of our citizens. So that corresponds with what the Romans did. Maybe someone who watched the show knows how it turned out in the real fictional world.
The West Wing is free on Netflix streaming. It is from the third episode of season one, titled A proportional Response. They wound up bombing a military air base, and the intelligence headquarters of the country as well as two other targets I think. There were no in show ramifications beyond that episode if I recall correctly. The West Wing dealt with so many topics that many topics/events in the show only lasted for one or a very limited number of episodes. Overall, it is a great show, one of my favorites, even if it has many such short lived plot points. Put it another way, none of the plot points are irrelevant to any critical thinking person, even if they only last one episode.
Yup. Basically Sheen is angry at the assassination of an Israeli minister (in retaliation for a covert killing by the US, no less) and gets tired of the traditional way of dealing with state-funded terrorism. For a while he wants, this time, to retaliate against one tragedy by pretty much wiping Not_Iran off the map, since demonstrably a proportional tit-for-tat response doesn’t deter enough. Hence the quote.
Then he comes to his senses.