For the second time this year, the European Central Bank has tightened its grip on borrowing costs, responding to inflation that has climbed to more than double its intended ceiling across the eurozone. The proximate cause lies not in domestic excess but in the distant fires of geopolitical conflict — energy markets convulsed by the US-Iran confrontation that began in late February have sent prices cascading through European households and businesses alike. The ECB finds itself in the ancient bind of institutions asked to solve problems that originate beyond their reach: raising the cost of mo