South Korea, US forces begin joint military drills

South Korea and the United States kicked off their annual, massive military exercises on Wednesday as North Korean leader Kim Jong-Un ordered his troops to prepare for a "merciless strike" against the enemy forces. The drills always raise tensions on the divided Korean peninsula and this year they come after the North's recent ballistic missile test and the assassination by nerve agent of Kim's half brother in Malaysia. Participation in the joint exercises -- known as Key Resolve and Foal Eagle -- is similar to last year, a United States Forces Korea spokesman said.