There are many weapons systems ROK could provide to Ukraine that would be helpful, but one of the most valuable contributions they could make would be a large scale delivery of 155mm artillery shells. They could give Ukraine enough ammo to get them through the next year, while the west ramps up its own production. They also have significant Air Defense systems, including some recently retired.
Romania has announced the decision to Transfer one of its four MIM-104 “Patriot” Surface-to-Air Missile Batteries to Ukraine.
https://x.com/sentdefender/status/1803770983796347369
Last year the US asked ROK to transfer KM-SAM batteries (based on Russian S-350/400) to Ukraine. After today’s announcement, maybe their No will change to a Yes. They also have some recently retired HAWK batteries.
That would be huge.
With the Norks depleting their supply of artillery shells, this should enable South Korea some latitude to reduce their supply.
Also, I believe South Korea should increase production of the K239 Chunmoo (HIMARs equivalent) and start drone development & manufacturing.