THE SECURITY SITUATION in the African Sahel — where U.S. commandos have trained, fought, and died in a “shadow war” for the past 20 years — is a nightmare, according to a Pentagon report quietly released late last month. It’s just the latest evidence of systemic American military failures across the continent, including two decades of deployments, drone strikes, and commando raids in Somalia that have resulted in a wheel-spinning stalemate and an ongoing spate of coups by U.S.-trained officers across West Africa that the chief of U.S. commandos on the continent said was due to U.S. alliances with repressive regimes.