REUTERS/Jonathan Ernst The alliance between the US and Europe flourished during the Cold War, but has cooled off since then. President Donald Trump drove the final nail in the coffin by withdrawing the US from the Iran nuclear deal. America's isolationist attitude could endure long after Trump is out of office. The Atlantic alliance, built to contain the Soviet Union in the aftermath of World War II, began to die when the Cold War ended. What kept it alive over the last three decades has been less strategic necessity than a convergence of values — the values of the liberal postwar order.