South Korean officials have repeatedly said Seoul has not been officially invited by Washington to join the US-led Quad group also involving Australia, India and Japan.

The line was repeated once again Sunday when the presidential office of Cheong Wa Dae denied a report by a Japanese daily newspaper that US national security adviser Jake Sullivan had strongly requested Seoul join the quadrilateral framework during a meeting with his South Korean counterpart Suh Hoon early this month.

Speaking on condition of anonymity, a senior official at Cheong Wa Dae said the report made earlier in the day was incorrect and didn’t reflect what was discussed between Suh and Sullivan.

But it is undeniable that US President Joe Biden’s administration has sent an unambiguous signal of its wish to see South Korea participate in the Quad, which it seeks to solidify as a key network of like-minded democracies against an increasingly assertive China. During his visit to Seoul last month, US Secretary of State Antony Blinken said the US was already working closely with South Korea on deepening cooperation on many issues in connection with the Quad.

Seoul is now seen to be trying to gloss over the diplomatic reality by denying Washington’s persistent pressure on it to join the group, citing the absence of formal and direct request. This attitude comes in the context of South Korea’s efforts to maintain an equal distance from the US, its key security ally, and China, its largest trading partner.

President Moon Jae-in’s government appears particularly cautious about being in step with the Biden administration’s push to form a web of allies and partners based on democratic values to keep a rising China in check. It is concerned that doing so would not only have a severely negative impact on South Korea’s economic interests but also hamper its peace agenda for the Korean Peninsula.

Moon Chung-in, a former special adviser to President Moon on foreign affairs and national security, said in an interview with another Japanese newspaper Sunday that it would be difficult to warrant peace and prosperity on the peninsula if South Korea stood by the US. He added that China then would become active in providing support for North Korea, amplifying the security burden to be shouldered by Seoul.

But there are growing concerns that the Moon administration’s ambiguous stance between Washington and Beijing runs the risk of relegating South Korea to a second-tier alliance with the US. Portending this possibility is a bill presented by US senators last week that would govern the fraught US relationship with Beijing. The Strategic Competition Act mentions Japan, Australia and other Western allies as partners with the US for substantial cooperative programs in various areas. But South Korea is barely addressed in the proposed bill except for the customary reference to it as a critical ally.

South Korea’s alienation from the US-led coalition of nations sharing democratic values would not help bring peace and prosperity to the peninsula.

It would only further embolden the recalcitrant nuclear-armed regime in North Korea to domineer over the South. China, in any case, is set to provide essential support for the North to prevent the implosion of the impoverished state suffering from international sanctions. Rather Beijing will seek to strengthen its sway over Seoul, which it sees as the weakest link in the network of allies and partners with Washington. In recent years, China’s military planes have more frequently intruded into South Korea’s air defense identification zone and its warships have reinvigorated operations in the waters between the two countries.

It should also be noted that security and economic spheres cannot be separated in the escalating strategic competition between the US and China. Being alienated from the US-initiated global supply chains excluding China would push South Korea’s high-tech industrial sectors into a severe predicament or could even bring them to a halt.

President Moon should be clear-eyed about the risks to be caused by Seoul’s prolonged ambiguity in its stance between the two superpowers.

Diplomatic sources here say consultations are underway between South Korean and US officials to arrange for the first summit between Moon and Biden in Washington next month. Moon needs to use the stage not to reiterate his administration’s ambiguous position but to make an unequivocal commitment to the South Korea-US alliance and Washington’s endeavor to form a network of democratic nations to enhance a free and rules-based global order.