SEOULâSouth Korea's top military official said Sunday that a torpedo likely exploded under the Cheonan, the South Korean patrol boat that sank a month ago near the maritime border with North Korea, edging Seoul even closer to declaring it was attacked by forces from the North. That would hasten a delicate decision about what to do next. South Korea faces several constraints in penalizing Pyongyang, starting with the prospect that a military response could escalate into a war that no one here wants. And the timing of a response may be shaped by an approaching election and the amount of time and effort it takes to rally international support for economic penalties. Defense Minister Kim Tae-young stopped just short of blaming North Korea for the March 26 sinking that killed 46 sailors. "I think the bubble jet effect caused by a heavy torpedo is the most likely cause," he said. Also Sunday, the lead investigator of the sinking said his team had concluded that a "non-contact" explosion tore the ship apart. A salvage crew on Saturday recovered the ship's second severed half, its bow, after raising its stern on April 15. http://online.wsj.com/article/SB100...5400833858626.html?mod=WSJ_hpp_LEFTTopStories