Last weekend the diplomatic world was agog at the refusal of Saudi Arabia's King Abdullah to accept a seat on the U.N. Security Council. Global disbelief gave way fast to clear understanding: The Saudis have decided that the United States is no longer a reliable partner in Middle Eastern affairs. The Saudi king, who supported Syria's anti-Assad rebels early, before Islamic jihadists polluted the coalition, watched Mr. Obama's red line over Assad's use of chemical weapons disappear into an about-face deal with Vladimir Putin. The next time King Abdullah looked up, Mr. Obama was hanging the Saudis out to dry...