Iran isn't getting help from their allies. Not in the way you'd think. And NATO is in agreement that Iran can not have access to nukes.
In what way does the U.S. look really bad? Preventing terrorists who want nothing more than to eliminate the western culture from having access to devastating weapons?
Seems like it's inching closer and closer to them getting help from their allies lol. Iran never had nukes, they were in negotiations when Israel pre-emptively struck them on the notion that Iran was days away from enrichment (Something that's been said for over 3 decades, as well as about Iraq, from the same guy too....)
As far as the U.S looking bad, the previous sentence is just one of many reasons.