Threatened by North Korean nuclear weapons and communist Chinese conventional air and missile fires, South Korea has decided to spend serious money on an old but often spurned military concept: the arsenal ship.

The concept is simple. Take a very large but comparatively inexpensive civilian commercial ship. Oil supertankers and huge container carriers fit the profile perfectly — they’re inexpensive when compared to navy warships.

Now pack the ship with vertical launchers and several hundred long- and mid-range missiles capable of destroying enemy shore targets and perhaps enemy surface ships. Add short-range air and missile defense weapons and presto, enormous sea mobile firepower bang for the buck, or in South Korea’s case, bang for their wons.

The arsenal ship concept has bred aerial arsenal concepts, with 747s and military transport aircraft (e.g., USAF C-5s) launching missiles a thousand miles from the target then fleeing. In some ways, the USAF’s 21st-century B-52s are arsenal planes. Russian air-launched missile attacks on Ukrainian cities demonstrate that long-range standoff attack can be deadly.

South Korea’s interest in arsenal ships isn’t new. But in mid-April, Seoul selected a design team and indicated it will buy three “joint firepower ships,” which is military lingo for arsenal ships. Instead of a commercial ship, South Korea may consider a modified destroyer hull. However, in April the Naval Market Forecast Newsletter noted that even if destroyer hulls are used, the ships will carry land attack cruise and ballistic missiles, not anti-submarine weaponry or anti-surface guns.

When they are built and deployed, South Korea’s ships will tell North Korea and China that a surprise attack will not destroy its ability to retaliate. North Korea focuses on South Korean land targets. Another message: Should South Korea feel threatened by imminent attack, the ships are offensive platforms capable of precision strike. Precision means striking within a few meters of the center of the target.

This month interestingengineering.com wrote that South Korea’s joint firepower ships are “similar” to the arsenal ship concept the U.S. abandoned in the 1990s.

That comment is accurate. I first encountered the arsenal ship concept in 1992 when I read an unclassified think tank paper on the concept. I was working as a consultant in strategic wargaming in the Office of Net Assessments. 1992 was Post-Desert Storm. The Soviet Union was recently kaput. 1992 was the era of The Peace Dividend. Many of us — yours truly included — were amazed the Cold War ended with a whimper and the bad guys lost.

I write this on memory. The paper’s author argued arsenal ships are cheap and quick to acquire. A merchant ship can become an arsenal ship bearing tremendous missile firepower that could support U.S. Navy battle groups. I remember thinking, if you can use a merchant ship, could you use a barge? One summer when I was in college, I worked offshore on a derrick barge in the Gulf of Mexico. The barges are huge — but slow and sitting ducks.

Seeking informed opinions, a naval expert told me arsenal ships are a new take on an old and worthwhile idea. But the U.S. Navy had little interest. Remember, this chat occurred in 1992 or 1993.
However, in 2002, to meet a strategic arms reduction requirement, the USN converted four “Ohio class” ballistic missile submarines into cruise missile carriers. Bye-bye, nuclear warheads. Now the Ohios carried Tomahawks with conventional munitions. Cold War “boomer” subs became a type of arsenal ship.

2023 in the Pacific: the USN confronts communist Chinese land and sea forces determined to prevent American carrier battle groups from approaching the Chinese coast. I think small, stealthy, fast attack craft armed with strike missiles foil China’s strategy.

But South Korean arsenal ships will give Beijing additional doubts, especially if they coordinate with small strike craft. And that’s a very good idea.

Austin Bay is a syndicated columnist and author.