Jet fuel prices have more than doubled since the US and Israel first attacked Iran in February. The reason: Both Iran and the US have at different points blocked the Strait of Hormuz , a key waterway for a fifth of the world's  oil and gas tankers. Marina Efthymiou, an aviation management professor at Dublin City University, told DW that jet fuel prices in Europe rose from about €68.27 ($80) per barrel in February to €153.84 ($180) at the end of April, according to the International Air