North Korea launch increases focus on risky U.S. shootdown option

By Matt Spetalnick and David BrunnstromWASHINGTON (Reuters) - North Korea's firing of a ballistic missile over Japan could increase pressure on Washington to consider shooting down future test launches, although there is no guarantee of success and U.S. officials are wary of a dangerous escalation with Pyongyang.More attention is likely to focus on the prospects for intercepting a missile in flight after North Korea on Tuesday conducted one of its boldest missile tests in years, one government o