NPR criticism is about raising the president's negatives and creating contrast; it's not at all about legitimate policy concerns.
Ambinder nails it on the NPR critics:
The NPR's reliance on the Nuclear Nonproliferation Treaty is predicated on strengthening the NPT's penalties for non-compliant states. Number three, it is actively pressing China and Russia to support sanctions against Iran and hasn't ruled out imposing tougher sanctions with Europe alone (whatever that would accomplish.) Number four, "directly confronting" means -- what, exactly? War? Say it aloud, senators, if that's what you intend. [emphasis my own]
But they won't, and they probably won't have to. This is about raising the president's negatives and creating contrast; it's not at all about legitimate policy concerns. As the critics all but admit, they can't allow Obama to have a political victory abroad. Not during the mid-cycle silly season.