North and South Korea exchange fire

A brief update that I'm sure you're all aware of: North Korea fired artillery on Yeonpyeong Island while South Korean marines were engaged in a military exercise there.  It sounds like two ROK marines were killed and they returned fire on the North with unknown effect.  So far the verbal response by the South Korean president Lee Myung-Bak has been very aggressive.  It is my opinion that South Korea should respond to this attack in the way they should have responded to the sinking of the Cheonan-- a decisive and disproportionate counter-attack (e.g. destroy North Korea's naval capabilities and/or decisive strikes on North Korea's artillery forces).  It is also my opinion that the United States should be right along side in this response to reaffirm our commitments to our South Korean allies.