The question is not one of legality, or even of morality.

Iran has essentially declared war on the United States and the attacked country can respond as it sees fit against Iran’s military or its surrogates.

The question is purely one of strategy, tactics, and diplomacy. Most importantly it involves the decision whether to widen the conflict that Iran began against the United States.

[Yes, they did — in 1979. They have fought the US through its proxies ever since, starting with Hezbollah’s attack on the Marines in Lebanon 40 years ago and the hostaging of Americans in the years afterward. The US has chosen to act as though there is no war, more at times than others, but that’s a strategic choice … one that’s not paid off in the long run. At the very least, we should stop appeasing the mullahs of Tehran, a policy that only results in wider conflict rather than conflict resolution. — Ed]