TEL AVIV/JERUSALEM/WASHINGTON (Reuters) — U.S. President Donald Trump and Iran threatened to escalate their war by attacking energy and desalination facilities in the Persian Gulf, a potential widening of hostilities that could deepen a regional crisis and add to concerns in global markets.Air raid sirens sounded across Israel from the early hours of Sunday morning, warning of incoming missiles from Iran, after scores of people were hurt overnight in two separate attacks in the southern Israeli cities of Arad and Dimona.The Israeli military said hours later that it was striking Tehran in response.The risks of worsening regional conflict, highlighted by an Iranian threat to hit water-scarce Gulf states'…