The dominance of the U.S. dollar has historically given Washington a major advantage in policing global business. Most international transactions denominated in dollars must be settled by American banks, giving Washington the ability to monitor them—and cut off users’ dollars through sanctions if necessary, crippling their operations. But U.S. adversaries are increasingly turning to China’s financial system and the yuan to conduct business. By bypassing the U.S.-led banking system, they weaken Washington’s enforcement powers. Beijing in 2015 launched a payments platform—the Cross-Border Interbank Payment System, or CIPS—that serves as an alternative to Swift, the messaging infrastructure that links the world’s banks.

Full investigation : A WSJ investigation revealed how Iran is increasingly using China’s financial system to evade sanctions and avoid Washington oversight.