North Korea wants to maintain its independence and opposes free trade. There is a risk of North Korea using nuclear weapons against South Korea or terrorist groups, which could lead to war between North and South Korea along with China and the US intervening. In March 2010, North Korea threatened to use missiles against the US and South Korea if they conduct annual military drills in South Korea. There are also concerns about the fate of North Korea's nuclear weapons if leader Kim Jong Il's health deteriorates further or upon his death.