[Someone]

It _may_ have deterred enemies from firing more rockets.

It _may_ (at the time) have boosted the confidence of allied and US soldiers on the ground.

It _may_ have been deemed necessary to do _anything_ that made the US’es allies think the US didn’t let them handle the threat alone.

If you want to claim to be the policeman of the world, this won’t help your reputation:

   USA    : “If war comes, we will protect you”
   Saoudis: “War came. Can you help us?”
   USA    : “Sorry, our rockets do not work”