I think this pullback is intentional. The problem with doing good things quietly is that nobody knows. If he just didn't do the strike at all, no one would know he decided not to because of the human cost. But by saying it was about to go down and he changed his mind, the media has to report it. They think most people are like, 'Look at Trump! He's so erratic!' Which is true.
But they don't understand most people are also in agreement that killing 150 people over an unmanned drone is excessive. The media is tickled pink to play that clip of Trump saying a strike would be disproportionate. Average Americans are more at ease that when it really mattered he made the right decision. And average Americans don't want another war.
It still baffles me that despite almost unanimously, except for the Neo Cons, Conservatives don't want war with Iran. Yet the left, deep in their echo chambers, still believe Trump wants a war to increase his support for reelection. Apparently it's 'too early,' and he wants to save the popularity bump for closer to the election because he's worried he might lose.
Why do libtards believe that nonsense? Because that's what they want to believe. They still haven't mastered the distinction between their desires and reality.