If the Iran war continues and oil reserves are drained, policymakers may have to use emergency tools to curb energy use, says Javier Blas for Bloomberg Opinion. LONDON: Five weeks into the Iran war, the math of oil-barrel counting is intractable: The world is short of the black stuff. Measures ranging from pipelines that bypass the Strait of Hormuz to tapping strategic reserves have offered a cushion. But unless the United States and Israel’s Iran conflict ends very soon, oil consumption needs