The ROKN participated in the fighting that followed, together with the navies of the United Nations coalition.
At that time, the ROKN was not yet able to wage modern maritime warfare beyond coastal seas; it was still too immature, the outbreak of the war having come immediately after its establishment.
With regard to large combatant ships, the ROKN had in 1951 only two outdated, World War II-vintage patrol frigates capable of operations on "blue water"--that is, on the high seas, away from home waters.
In spite of these handicaps, the ROKN took great pride, and found a strong spiritual foundation, in the fact that though the smallest service in the South Korean Armed Forces, it had engaged in combat with great courage and effectiveness in the war's most difficult period, the first years after the state's establishment.
Over the next two decades, the ROKN continued to build its fleet as a main pillar of deterrence against invasion by North Korea, in full compliance with its national defense commitments under the ROK-U.
Around 1960, the ROKN beefed up the numbers of both DEs and PFs and increased its force of patrol boats, such as PCs.
In the late 1970s and early 1980s, the ROKN received from the U.
Perhaps at this time the ROKN preferred to improve its capability in surface combat rather than that in ASW.
The ROKN might have based such an assessment on an internal evaluation based on shared national origin--that is, on unique insight, unavailable to analysts of other navies--of the operational capability of the North Korean navy.
Apparently, the ROKN was uninterested in building up its MCM force.
In these years the Republic of Korea participated in the Vietnam War, with the ROKN deploying transport ships to the South China Sea.