As debate rages among politicians and pundits in Washington over whether to endorse last month’s historic nuclear compromise with Iran, key European allies have already given their verdict: a resounding thumbs up. Government ministers and business leaders in France, Germany, Italy and elsewhere in the EU are racing to open up a new era of diplomatic, trade, investment and possible future military cooperation with Tehran, regardless of what American and Israeli sceptics say. While Americans argue over timescales, technicalities and Iranian trustworthiness, behind their backs the scramble for Persia, recalling Europe’s 19th-century scramble for Africa, has already begun. The cohesion...