In a targeted joint operation conducted Friday in Nigeria’s volatile Lake Chad Basin, U.S. and Nigerian security forces have eliminated Abu Bakr al-Mainuki, one of the highest-ranking leaders of the Islamic State West African Province (ISWAP), U.S. President Donald Trump announced in a late-night social media post. While Trump’s announcement offered few immediate operational details, it marked a major milestone in counterterrorism efforts across the Sahel region, where IS-affiliated militants have expanded their influence in recent years.