U.S. Special Envoy for the Horn of Africa Mike Hammer returned to Ethiopia, 12 days after fighting resumed between federal forces and Tigrayan rebels, breaking a monthslong cease-fire. The renewed clashes have quashed hopes for peace talks and threaten…

Frances Tiafoe ended Rafael Nadal’s 22-match winning streak at Grand Slam tournaments by beating the 22-time major champion 6-4, 4-6, 6-4, 6-3 in the U.S. Open’s fourth round Monday.Tiafoe is a 24-year-old from Maryland who is seeded 22nd at Flushing M…