Much like its northern neighbour, South Korean's armed forces have long been overwhelmingly defensively oriented, the primary task being to defend the country in the event of an inter Korean conflict. While both Koreas are among the world's foremost military powers (ranked Tier Two powers well within the world's top ten), both have long neglected investment in extra peninsular power projection. This is despite it being well with in the capabilities of both countries, with advanced shipbuilding capabilities and highly capable long range combat aircraft, to do so. Unlike North Korea however, South Korea has in recent years made a gradual departure from this heavily defensive stance and begun to invest in capabilities to deploy force overseas. The end of the Cold War and unlikelihood ever since of a North Korean attack, coupled with a far larger economy which could support a greater defence budget, were key factors in this. Investment in power projection capabilities initially began in the early 2000s with the upgrading the navy from a coastal defence force to a major blue water force fielding high endurance warships capable of offensive operations far from Korean shores. Then President Kim Dae Jung had in 2001 expressed his goal to make South Korea a world power by building a navy which "will defend the national interests in the five oceans and perform a role in defending world peace" the country has since built two highly sophisticated aircraft carriers under the Dokdo program alongside some of the world's most capable destroyers including the Sejong the Great Class, Chungmugong Yi Sun Sin Class and Gwanggaeto the Great Class. This gave the Korean Navy the fifth largest destroyer fleet in the world, supported by advanced Inchoen Class frigates and Type 214 submarines to form some of the most dangerous carrier strike groups in the world.
Alongside investments in naval power projection, South Korea has also commissioned heavy tankers aircraft for its air force to allow the service to conduct operations well beyond the Korean Peninsula. While the country's F-15K Slam Eagle elite strike fighters, the backbone of the country's aerial warfare capabilities and some of the most advanced platforms of their kind, have a considerable range allowing them to strike targets not just in North Korea but also across Japan and much of China, this range is set to be further extended by allowing these heavy platforms to refuel mid flight. South Korea's lighter and shorter ranged platforms such as the F-35 and F-16, already well within their limits to strike North Korean targets, will also be able to benefit from an extended range which will allow them to strike targets across East Asia.
The acquisition of European made Airbus A220 MRTT aerial tankers is the first of its kind in the history of the South Korean Air Force, and likely represents grander ambitions for the country's armed forces beyond being able to confront their formidable northern neighbour in an intra peninsular war - for which tankers and other recently procured assets such as long range destroyers and Dokdo Class carriers are of little use. Four tankers are set to be acquired, which will between them be able to fuel sixteen fighters for long range missions. The A220 MRTT is full compatible with combat aircraft operated by the Korean Air Force, and each tanker can carry up to 111 tons of fuel of which it can offload 50. It can do so at ranges of 1,000 miles, and has a 4 hour loitering mission time.
One possible explanation for South Korea's investment in long range power projection capabilities is that it has been carried out in response to the emergence of Japan as a major military power, particularly under the remilitarisation program currently being undertaken under Prime Minister Shinzo Abe, which has prompted South Korea to invest in extra peninsular war fighting capabilities. A formidable destroyer fleet and the ability to deploy carrier strike groups is key to denying Japan complete blue water control, with Korea's larger neighbour to the east fielding the third largest destroyer fleet in the world and already deploying four carriers of its own, two of which were designed to deploy fixed wing fighters at sea. Japan's leadership has also indicated interest in pursuing further carrier programs to produce larger warships in future. Aerial tankers, while not needed by Korean F-15s, would be essential to facilitate offensive operations by lighter platforms in support of the Slam Eagles should they seek to operate offensively against Japanese targets - counterbalancing the formerly overwhelming advantage held by Tokyo's sizeable fleet of long range F-15J air superiority fighters.
An alternative explanation is that South Korea seeks greater independence in its military affairs, as strongly supported by the current administration of President Moon Jae In, and with the United States having deployed its forces to the country for almost 75 years only the development of advanced 'great power capabilities' similar to those deployed by the U.S. military to the peninsula can the country better position itself to take full charge of its own defence. This could potentially lead to the withdrawal of the U.S. military entirely, or at the very least the restoration of wartime operational control to South Korea, both of which high ranking members of President Moon's administration have indicated may well be part of the administration's final goal.