The U.S. has suggested considering another delay in the transfer of wartime operational control to South Korea, but apparently with a precondition that Seoul finds hard to accept.

Top U.S. officials have recently increased pressure on Seoul to join the Pentagon-led global missile shield program, implying that its participation would facilitate discussion on putting off the OPCON handover slated for December 2015. They cite the need to counter threats from North Korea’s ballistic missiles, but South Korea’s decision to join the multilayered missile defense scheme is certain to strain its ties with China. For Seoul, it is a more reasonable choice to establish a separate low-tier defense system against Pyongyang’s threats.

South Korean and U.S. defense chiefs appeared to have gone as far as was allowed by current conditions by sharing the need to reconsider the timing of the OPCON transfer and agreeing to continue specific consultations during their annual Security Consultative Meeting in Seoul on Wednesday.

Wartime operational control was originally set to be handed over to Seoul in April 2012. But Seoul asked for a rescheduling shortly after North Korea’s deadly torpedo attack on a South Korean warship in 2010. Washington accepted the request.

As this paper has noted, the OPCON transition should be a process absolutely free of any potential risk. The decision on the right timing must be tied to critical security variables such as Pyongyang’s third and latest nuclear test in February rather than dates previously agreed upon. Maintaining the current allied defense structure would be more effective in resolving the North Korean nuclear problem and could remain an essential buffer against a possible failure to denuclearize the North.

Building an effective global missile shield may be a top strategic priority for U.S. officials. But their move to tie Seoul’s participation in the program to an agreement to delay the OPCON transfer would hardly sound persuasive to the South Korean public.

Seoul and Washington need to strengthen coordination to ensure that their alliance will not be affected by a possible entanglement of the two matters. As some experts suggest, consideration may be given to heightening the interoperability between the U.S.-led joint missile shield and South Korea’s separate system.