Why should it be surprising that South Korea is building a blue water navy?
Is the South Korean Navy simply an expensive trifle?
Last week, Kyle Mizokami argued that the Republic of Korea Navy is “Impressive … and Pointless.” Mizokami makes the nutshell case against South Korea’s shift to the sea: "In the country’s rush to embrace its destiny as a seagoing nation, South Korea has prematurely shifted resources from defending against a hostile North Korea to defeating exaggerated sea-based threats from abroad. Seoul is in the midst of a strategic shift that has shorted defenses against the North and put its forces in harm’s way."
We benefit from a global economic order run under rules we set, so our power projection forces defend our interests just by being out there seen defending the world order we designed after World War II.
As South Korea's trade has gone global, why is it shocking that South Korea feels a need to have a navy that can contest any efforts to cut them off from the rest of the world?
Yes, there is a point that having a navy would be pointless if North Korea drove south through inadequate South Korean ground forces backed by insufficient air power.
But that isn't the situation, is it? North Korea's military power has rotted away over the last 20 years while South Korean ground power has expanded in quality.
The only reason North Korea still poses a threat is because South Korea's capital, Seoul, is within artillery range of North Korea.
And Seoul has a quarter of South Korea's population (if memory serves me).
But I don't believe North Korea has the ability to take Seoul unless they make massive use of chemical weapons and that use causes the near-complete collapse of the South Korean army. If that happens, North Korea might be able to organize a largely unopposed road march into Seoul.
North Korea's only real option is to bombard Seoul and hope to extract concessions to stop the bombardment--and achieve that before South Korea with American support advances north of the DMZ to create a no-launch zone that protects Seoul.
In the future, North Korea will develop a nuclear warhead and have that threat. But that is in the (near) future. And how useful will that be in extorting cash when South Korea has to know that their only hope at that point is a North Korean collapse?
Anyway, South Korea has the need and room to breathe to build a navy. A navy that will have anti-missile capable ships, I'll add, if you can't look away from the DMZ (demilitarized zone).