U.S. stocks opened flat on Wednesday, but managed to edged higher in morning trading after global shares pared gains on renewed concerns that the U.S. was moving closer to launching military action in Syria.On the economic calendar, economists will look to July's trade report and motor vehicle sales figures for August. Also, the Federal Reserve will publish the latest edition of the Beige Book at 2 p.m. Eastern.The Dow Jones industrial average gained 59.58 points or 0.04 percent, to 14,893.54. The S&P 500 rose 8.46 points or 0.52 percent, to 1,648.20. The Nasdaq Composite added 22.12 points or 0.61 percent, to 3,634.61.