An escalating conflict in the Middle East rattled global markets on Monday, as the prospect of a long-drawn fight drove energy prices higher and hammered travel stocks and regional assets. Israel attacked Lebanon in response to strikes by Hezbollah, while Tehran fired missiles and drones at Israel, Gulf states and a British air base in far-away Cyprus. U.S. President Donald Trump said the military campaign against Iran could continue for the next four weeks, according to an interview on…