Last week, over 60,000 migrants — mostly military-age men — surged into Ceuta, a Spanish city of just 84,000. They swam around sea barriers, climbed fences, and charged the land border in a chaotic rush that briefly swelled the enclave’s population by more than half. Dozens died by drowning or in the crush. Local authorities were overwhelmed. Spain’s government scrambled the military and police. A human wave briefly swallowed a tiny European outpost on the edge of Africa. 

That is not a faraway tragedy. It is a warning shot for us.