A battle for control of Yemen’s coastal plains overlooking the strategic Bab el-Mandeb Strait, launched on Friday by Iran-aligned Houthi rebels, is rapidly intensifying into an all-out war with Saudi-backed government forces. A wave of Houthi missile and drone strikes launched against four cities in southern Saudi Arabia early on Tuesday, injuring 73 civilians, may prove to be the tipping point in the conflict, analysts say. Coinciding with an escalating battle of attrition between the United...