Barack Obama’s decision to abstain from, and therefore allow, last week’s vote to censure Israel at the U.N. Security Council is a fitting capstone for what’s left of his foreign policy. Strategic half-measures, underhanded tactics and moralizing gestures have been the president’s style from the beginning. Israelis aren’t the only people to feel betrayed by the results.

Also betrayed: Iranians, whose 2009 Green Revolution in heroic protest of a stolen election Mr. Obama conspicuously failed to endorse for fear of offending...