In the short run, Obama simply has to win enough votes for his Iran deal. For the long run, he has to persuade Americans that diplomacy is a safer path than war.
Greece may be better off outside the eurozone: Austerity policies have generated a catastrophic collapse of GDP, a worsening of unemployment, and bank shutdowns.
The deal struck by the United States and its partners with Iran to dismantle that nation's capacity to build a nuclear weapon looks like a remarkable achievement.