The US leader was rebuffed last month when he demanded private guarantees that no strike would go ahead without White House notification, suggesting Israel no longer plans to "seek Washington's permission", sources said. The disclosure, made by insiders briefed on a top-secret meeting between America's most senior defence chief and Benjamin Netanyahu, Israel's hawkish prime minister, comes amid concerns that Iran's continuing progress towards nuclear weapons capability means the Jewish state has all but lost hope for a diplomatic solution.