Antwerp, now the No. 1 port in Europe for cocaine busts, has seen a rise in gang violence and corruptionANTWERP, Belgium—For centuries, goods flowing through the giant port here have enriched this elegant city, known for its diamonds, art and fashion. Now a different import from across the Atlantic—cocaine—has unleashed a gusher of cash that officials say is swamping Antwerp with corruption, violence and economic distortion. Authorities have seized 88 metric tons of cocaine stashed in containers from Latin America this year, nearly 10 times the figure in 2014. .... To sneak their drugs through the port, traffickers are paying...