Reply #8: here's another complication

[drumwolf]

If the general population was as hostile as the Iranian government, it would be easier to say, "OK, we should get tough on Iran."

But we need to consider that most of the population loathes the mullahs and is more sympathetic than not to the West. If we can hold off as long as possible without getting aggressive with the mullahs, it would be much better to cultivate the good will of the Iranian people who will probably at some point replace the mullahs with a friendlier government down the road. Invading Iran would scuttle any chance of that.