Money laundering is a multi-bank phenomenon. Danske Bank Estonia has been revealed as the hub of a $234bn money laundering scheme involving Russian and Eastern European customers. But Danske Bank Estonia couldn’t do this by itself. Much of the money was paid in U.S. dollars, and for that, it needed help from other banks. Banks that had access to Fedwire, the Federal Reserve’s electronic settlement system. Big banks, in other words. It appears that four big banks helped Danske Bank Estonia make its dodgy transactions. J.P. Morgan, Bank of America and Deutsche Bank AG all made dollar transfers on behalf of the Estonian branch’s non-resident customers. And according to the Wall Street Journal, Citigroup’s Moscow branch…….