The attack between South Korea & North Korea

I think this is north Korea's fault. They began to attack Yeonpyeong Island. Just my thoughts...

what I believe is that there will be a war between North and South Korea. South Korea tried to support North Korea, but North Korea attack just because South Korea haven't provide them rice once. On March 26th North Korea attack South Korea's ship (chun an ship) in Bek Ryung island and killed about 50 mariners who were in there. at that moment, the president of South Korea declared that there will be a war between South Korea and North Korea if North Korea attack them again. However, though North Korea have attacked south Korea and killed 2 armies and 5 citizens in yeon pyong island, South Korea isn't showing any strong decisions toward North Korea's attack and didn't even pay back on them. I believe the war between South and North Korea is depend on the president on South Korea, whether he will take the risk of war or not. because North Korea has nuclear bomb, it is not easy decision to decide. However, it is a fact that UN will be on side of South Korea, so there isn't much problem to think about. what I think is that South and North Koreas fight won't end unless there will be reunification between them or either side of Korea takes over another Korea. therefore, there should be a war between them in order to stop the war between south and north Korea. these are just my thought