On a clear day, residents of Yeonpyeong Island can see North Korea, 10 km away. They can also sometimes watch South Korean warships chase North Korean and Chinese fishing boats. These waters in the Yellow Sea are among the world's richest for blue crab.

Lately, however, North Korea has been making life riskier for residents of this fishing community. On May 22, they were ordered into bomb shelters after the North fired artillery shells around the island, without hitting anything. Earlier that week, the South Korean Navy fired 10 warning shots at North Korean ships after they crossed the maritime boundary between the two sides.

The line was drawn up unilaterally by the U.S.-led United Nations command after the 1950-53 Korean War. That conflict ended in an armed truce that has continued until now, leaving the two Koreas in a technical state of war.