419 Scam After meeting with Nigerian President Muhammadu Buhari yesterday, President Donald Trump said with confidence that Africa’s most populace country will “rip down” its barriers to U.S. agricultural exports. The boast seems highly unlikely to come to fruition for several reasons:

Nigeria’s tariffs are harmonized with the 15-member Economic Community of West African States. While Nigeria applies an average duty of 15.5 percent on agricultural imports, a 35 percent duty is permitted on items that the government wants to protect. Nigerian domestic politics exerts a great deal of influence in favor of import protection (poultry, pork, beef, vegetable oil, etc.).

President Buhari offered up an advance payme...