North Korea tested, for the third time this year, it's modified version of the Chinese HY-2 "Silkworm" anti-ship missile. The original HY-2 had a range of 100 kilometers. The North Koreans have extended the range to 150 kilometers and apparently improved the guidance system. Moreover, U.S. arms inspectors in Iraq have discovered several missile modification programs the North Koreans were doing for Iraq. One involved turning 300 Iraqi HY-2 missiles into cruise missiles with a 1,000 kilometer range. This was being done by replacing the liquid fuel rocket motor of the HY-2 with a gas turbine (jet engine) from Russian Mi-8 helicopters. The North Koreans have developed quite a bit of skill at modifying Russian missiles. All of their long range missiles are basically modifications of basic Russian models. They are not known to have done very spectacular work with guidance systems, but they might have some surprises there. There are a lot of guidance system technologies that can be built with off-the-shelf components. Thus it's quite possible that the North Korean HY-2 not only has longer range, but a more powerful guidance system. This would make it rather more dangerous for any ships getting within 150 kilometers of the North Korean coast.