The start of the year has not been an easy one for financial markets. The Federal Reserve is continuing its policy of trimming its bond purchases by $10 billion a month, and the immediate result has been a sharp pullback of the currencies, and to some degree equities, of countries such as Indonesia, Turkey, India, South Africa and Argentina. The reason? According to traders, commentators, and even the head of Brazil’s central bank, Fed policy will trigger interest rate rises around the world, staunching the flow of easy money that has purportedly fueled global growth — and leading to struggles everywhere.