There has a been a pretty vibrant debate in South Korea over building an indigenous aircraft carrier. That debate has been especially resonant where I live – Busan – because it would probably be built here.
IMO, the best argument for a ROK carrier is China’s creeping, long-term effort to dominate the South China Sea. Oil from the Persian Gulf traverses the SCS on its way to East Asia’s democracies – Japan, South Korea, Taiwan. Chinese control of the SCS oil sea lane would allow the PLAN to embargo carbon imports for whatever bogus reason Beijing could think of.
We can be sure that Chinese bullying in the region will use this tool as soon as China consolidates control of the SCS and puts up enough bases to launch blockades. Indeed, I have long thought that this is the primary reason China wants to control the SCS so badly. It’s not clear that there are a lot of natural resources in the seabed there or that they can be cost-effectively extracted. And all the little islands and sandbars in the SCS aren’t valuable in themselves.
But this would require SK to start seriously thinking about 1) power projection southward, 2) contesting Chinese sea control inside the first island chain, and 3) cooperating with Japan which is also threatened by this and which has a larger navy. That would all be great but is a big ask for a country not used to thinking about foreign policy much beyond the peninsula. And that is my big concern: that the previous Moon administration really wanted to build this because Japan is building an aircraft carrier, and wants to park it next to Dokdo. That is the wrong reason to build one.
Here is the original, pre-edited version of my essay from the Japan Times:
South Korean has considered, in the last year, constructing a light aircraft carrier. This has provoked controversy. The decision to build it or not has swung back and forth. The South Korean navy very much wants it and has made a public push for it. The South Korean legislature, the National Assembly, ultimately decided to fund it last year. But the government of new President Yoon Seok Yeol is apparently re-considering.
South Korea the Land Power
Most countries in the world lean into either land or sea power, as dictated by their geography. Unsurprisingly, island states develop ‘blue water’ (i.e., ocean-going) navies. Japanese modernization, for example, lead to maritime power in the last century and half. Britain too had a large navy at its peak.
South Korea would appear to fit into this box. It is an island of sorts. It has just one land border, but that is tightly sealed. So strategically, South Korea is nearly an island.
But necessity has made South Korean a land power nonetheless. Its border with North Korea is the most militarized place on the planet. The North Korean army numbers over one million active-duty soldiers, with millions more in reserve. North Korea’s air and naval power are small in comparison. A second Korean war, like the first one, would mostly be fought on the ground.
South Korea’s Widening Horizons
As countries become wealthier, they inevitably have wider-ranging interests. Rising states often have overseas trading relationships, often for particular resources which are unavailable at home. For South Korea, like Japan and many others, that means the import of raw materials, especially petroleum.
Petroleum imports to South Korea (and Japan and Taiwan) come mostly from the Persian Gulf, from exporters like Saudi Arabia. The oil tankers enroute to northeast Asia sail through the India Ocean and the Straits of Malacca, before turning north to pass through the South China Sea toward their destinations.
This is a critical sea lane for northeast Asian democracies, because China has made increasingly aggressive moves in the last decade to consolidate control over the South China Sea. As is now well-known, China claims nearly that entire sea, reaching all the way south to Malaysia and Indonesia.
This exorbitant claim has been found improper by the Permanent Court of Arbitration (in 2016), but China has ignored that ruling. It continues to take control of the various reefs, shoals, and islands in the South China Sea. It is militarizing them with docks, troop facilities, and airstrips.
The US and its allies have responded with ‘freedom of navigation operations’ (FONOPs), but this has not stopped Chinese expansion. A major Chinese militarization of the South China Sea could give it the ability to halt oil shipments to Japan, South Korea, and Taiwan with a naval blockade. That prospect has slowly sucked Japan into the South China Sea, and now it is pulling in South Korea too.
South Korea, traditional land power, must now contemplate projecting power further afield to contest Chinese naval threats to its crucial sea lanes. This is the core of the argument for the carrier, and it is a strong one – one Japan would be wise to consider more fully too.
South Korean/Japanese Cooperation in the South China Sea?
Although the US Navy has been at the forefront of FONOPs, the strategic threat is greatest to Japan, South Korea, and Taiwan. All are deeply dependent on oil for their modern industries and transportation. Relying too much on Chinese goodwill, or on the US willingness to fight for another country’s sea lanes, is obviously risky. The US alliance with South Korea and Japan is primarily about territorial integrity, not a wide-ranging defense of their import traffic. South Korea and Japan would be wise to consider developing some capability to act independently in defense of their own needs. A South Korean aircraft carrier is a first step in that direction for Seoul.
Ideally, this would involve trilateral cooperation. The US has long sought South Korea and Japan to cooperate better on regional issues. In his visit to East Asia last month, American President Joseph Biden once again emphasized trilateralism. Given that Seoul and Tokyo share nearly identical interests in the South China Sea – keeping it open to free commercial navigation – it should not be too hard to find basic ways to cooperate there. There was some minimal, ‘out of area’ South Korea-Japan cooperation a decade ago in the multilateral effort against Somali pirates in the India Ocean.
Interservice Competition: Will the North Korea Threat Derail a Carrier?
The biggest threat to a South Korean carrier is the cost. It will likely cost 2 billion USD to construct and another 50 million USD per year to maintain. And defense industrial costs are almost always too low, so those figures will likely go up.
The National Assembly has already worried that this is too much money. As North Korea continues its nuclearization and missilization, their will be corresponding pressure to build out South Korea’s own missile and missile defense forces. Those too are expensive. One THAAD anti-missile battery (Terminal High Altitude Area Defense) costs more than one billion USD. Ideally, the National Assembly would expand South Korea’s defense budget, but that is politically tough.
So ultimately, this debate will likely devolve into an interservice turf war, as the army and air force claim that local North Korea threats outweigh vague Chinese threats further afield. The North Korean threat school may win this time, but I would be surprised if South Korea (and Japan) did not conclude fairly soon that they need to be able to project air and naval power southward also.