The presidency of Barack Obama appears to be unraveling, writes Richard Fernandez...first the UK parliament, then both parties of Congress balked at his Syrian policy. Then Putin humiliated him so badly internationally that he retreated to the safety of domestic policy. But worse was to yet come: Rouhani, the Iranian leader, boarded a plane home having refused to meet the President of a country he had just visited and demonstrating to all and sundry you could beard the president of the US on his own home turf without apparent consequences. Read it all.