Houthi rebels vowed "escalation" in reaction to U.S. and U.K. strikes launched in Yemen on Sunday. A spokesman for the Iran-backed group vowed to continue its campaign of disrupting regional trade "no matter the sacrifices it costs us." The U.S. and U.K. launched a series of attacks on Houthi targets in Yemen this weekend in reaction to a lethal drone attack on a U.S. base in Jordan last week. "The US-British coalition’s bombing of a number of Yemeni provinces will not change...