The U.S. has been the tortoise in a global race for economic growth, plodding out a slow but steady expansion while China signals exhaustion and the rest of the world wobbles. Now, market turmoil and China’s troubles threaten to undermine the already unspectacular U.S. outlook. Few economists see a U.S. recession. In fact, some recent developments, including lower oil prices, will help U.S. consumers and businesses. But an uneven global growth outlook is pushing the value of the dollar higher, making U.S. goods more expensive overseas and harder to export. That could restrain the U.S. economy in the months ahead. Stock-market declines could further hurt U.S. consumer sentiment and spending, if the drops are sustained, and they make businesses even less willing to invest. Federal Reserve officials now need to decide if they should alter their planned course on interest rates. Officials have been signaling for months that at […]