South Korean foreign policy signalling: The rise and fall of unreciprocated costly signals between 2013 and 2023

Over the past decade, the government of the Republic of Korea showed a puzzling attitude towards foreign policy signalling. Seoul did not demand costly signals from Beijing and Pyongyang to ascertain their cooperative intents. Moreover, Seoul showed eagerness to unilaterally send the rivals costly signals to convey its intention to cooperate. We aim to explain Seoul’s engagement in unreciprocated costly signalling that diverges from mainstream theoretical expectations. We argue that the unreciprocated signalling stemmed from Seoul’s belief that Beijing and Pyongyang might not know its own cooperative intent, whereas the latter two countries’ cooperative intents were already sufficiently clear to Seoul. Therefore, Seoul reasoned that sending costly signals was crucial to convince Beijing and Pyongyang of its trustworthiness whereas such signals from the rivals were unnecessary. To support this argument, we draw on interviews with senior Republic of Korea officials, along with primary and secondary documents available in Korean and English.