Tokyo stocks plunged Wednesday, with the Nikkei index sinking over 2 percent, on selling fueled by concerns over the escalating tensions in the Middle East. The 225-issue Nikkei Stock Average ended down 843.21 points, or 2.18 percent, from Tuesday at 37,808.76. The broader Topix index finished 38.82 points, or 1.44 percent, lower at 2,651.96. On the top-tier Prime Market, decliners were led by electric appliance, air transportation, and bank issues. The U.S. dollar at one point climbed to the lower 144 yen range as the Japanese currency was sold after new Prime Minister Shigeru Ishiba said Tue…