China has launched the first submarine in a new class of nuclear subs designed to fire intercontinental ballistic missiles, U.S. defense officials said. The submarine is, at a minimum, months away from having missiles installed and going on a cruise, one official said Friday, discussing foreign weapons developments only on the condition of anonymity. Still, it is further evidence of China's intentions to expand both its nuclear weapons and submarine forces, officials say. It was widely known that China was building the new class of nuclear-missile submarine, called the "Type 094," but the launch is far ahead of what U.S....