Pakistan’s attempted role as mediator between Saudi Arabia and Iran is a delicate balancing act. A request from Saudi Arabia to join the Arab coalition bombing of Yemen was sensibly turned down. But the kingdom is a generous benefactor of Pakistan. Pakistan shares a long western border with Iran, and after Iran, it counts the second-largest Shia population of any Muslim country. Crucial to Pakistan’s interests is the Iranian proposal to build a rail-link through Baluchistan, to its strategic Arabian Sea port of Gwadar. Prime Minister Nawaz Sharif is a wily politician. Can he manage to balance both countries without antagonizing either?