Korea's home-built substitute for US CEC will leave out its Aegis destroyers

Existing tactical data links let ships share situational data, but they cannot fuse it or control an engagement ^[7]. CEC does both ^[6]. It merges target data from the radars and optical sensors of friendly ships and aircraft and shares it in real time over a high-capacity network ^[6]. A destroyer can then fire on a target that an aircraft far ahead of it has detected ^[6]. Without it, the Seoul Economic Daily wrote, "an Aegis destroyer has difficulty detecting and intercepting air targets beyond the horizon on its own" ^[8].

Australia's Hobart-class and Japan's Maya-class destroyers already carry the system ^[4]. Japan plans to fit it to the Aegis ships it is now building and link them with the ones it already has ^[9]. The paper set Washington's refusal beside remarks by U.S. Ambassador Michelle Steel, who told an alliance conference in Seoul that the alliance was "forged through war" and "built because American and Korean soldiers stood side by side defending freedom and shed blood together" ^[1].

Korea's answer is to spend at home ^[10]. Without CEC, the Navy is building a Korean naval integrated air defense system, to be installed mainly on the KDDX destroyer and Ulsan-class Batch IV frigates, ships fitted with Korean-built radars and combat systems ^[10]. Of the four Korean classes the report names, the system goes on the two Korea designed and cannot go on the two Aegis classes, Sejong the Great and Jeongjo the Great ^[1]. Those two are the Navy's mainstay ^[11].

On this evidence the refusal adds a second program beside the Jeongjo build. The report does not give a cost, a schedule or a contractor for the domestic system, and it does not say the Jeongjo program has been cut. So far the money moves to whoever builds the Korean network, and the Jeongjo hulls keep their US combat systems with no fusion network ^[10][11].

The outcome can still move. Washington could approve the sale: its reply cites policy, and it has already applied that policy differently to Japan and Australia ^[3][4]. Korea could build a bridge between its system and the Aegis combat systems, though the Navy now says its system cannot be linked to those ships ^[11]. Or the fleet could run as two networks, as the Navy's own plan describes ^[10][11].

I'd expect the split fleet. It is the plan the Navy is funding ^[10]. The paper also reported that a fleet mixing Aegis destroyers with KDDX and Ulsan-class Batch IV ships will operate less efficiently as a result ^[13]. The case against that view is that Korea ends up owning a network it controls and can extend to each new domestic hull, while imported CEC would have stayed subject to US export policy ^[3]. The view is wrong if the Sejong and Jeongjo classes end up on a fused fleet network by either route.