NIGERIA, Dec. 10 -- Somewhere along the stretch of brown waters where the River Niger folds into the restless heart of the country lies a facility that should have changed Nigeria's economic story. It sits there-massive, fully built, tested once, and left in the silence of unfinished intent. They call it the Onitsha River Port.

Every rainy season, the river rises like a promise. Barges drift in cautiously, officials dust off old ledgers, and economic activity flickers. Then the water level falls, and with it, the illusion collapses. Billions spent on dredging become a line item-a forgotten chapter. The gates close again. The nation nods and moves on.

But the real danger isn't the rising and falling river-it is what lurks on it.

Somewhe...