North Korea's Kim declares sub missile launch 'greatest success'

By Jack Kim SEOUL (Reuters) - North Korean leader Kim Jong Un supervised the test-firing of a submarine-launched ballistic missile and declared it "the greatest success," which puts the country in the "front rank" of nuclear military powers, official media reported on Thursday. North Korea fired a submarine-launched ballistic missile (SLBM) on Wednesday which flew about 500 km (300 miles) towards Japan. The South Korean government and experts said the launch showed technical progress in the North's SLBM program.