South Korea must move beyond partisan division to tackle security threats
South Korea’s internal political instability leaves it vulnerable to rising security threats including North Korea’s military alliance with Russia, China’s growing regional influence and the United States’ unpredictability under President Donald Trump. South Korea needs a firm and cohesive security strategy that aligns with the US and Japan. Otherwise, it may suffer irreparable damage.
North Korea’s nuclear advancements pose the most immediate threat. In January, Pyongyang launched what it claimed to be a hypersonic missile, which flew 1000km across Japan’s exclusive economic zone. During Joe Biden’s term as US president, South Korea increased military and intelligence cooperation with the US and Japan to enhance extended deterrence. Military information sharing, the US-South Korea Nuclear Consultative Group and the deployment of US submarines have all been important responses to North Korea’s growing arsenal.
However, uncertainty has grown since former South Korean president Yoon Suk-yeol—an advocate of the Korea-US-Japan trilateral mechanism—was impeached. The return of Trump’s transactional approach to international partnerships has worsened this unease. Should US leadership withdraw, South Korea and Japan must take the lead together to maintain regional security. South Korea’s strong army and THAAD missile defence, combined with Japan’s formidable navy and Aegis destroyer fleet, can strengthen collective security in East Asia amid intensifying tension.
The challenge comes from South Korea’s sharp partisan divide. Critics argue that Yoon’s efforts to normalise relations with Japan have compromised historical justice and compensation for victims of Japanese colonialism. The opposition uses historical grievances to mobilise anti-Japanese sentiment against the conservatives.
They also believe that stronger military ties with Japan will raise tensions with China and obstruct peacemaking with Pyongyang. This argument was prominent in the initial impeachment resolution, which attacked Yoon for being too pro-Japan and antagonising North Korea, China and Russia.
North Korea has long used these divides to destabilise South Korea’s relationship with Japan and undermine their efforts to counter Pyongyang’s operations. During the Japan-South Korea trade dispute, North Korean intelligence directed its espionage ring in Seoul to intensify anti-Japanese sentiment by organising protests and social media campaigns. If South Korea’s partisan division continues to strain its relationship with Japan, it will only embolden North Korea’s nuclear expansion and alliance with Moscow.
This division has also impaired South Korea’s military apparatus. Ex-defense minister Kim Yong-hyun was convicted for his part in the martial law crisis, leaving a leadership void in national defence. The opposition subsequently demanded an independent investigation of military operations, such as broadcasting propaganda over loudspeakers near the North Korean border. They accused the military of treason, suggesting that these operations were designed to provoke Pyongyang and start a war. These controversies are undermining public trust and demoralising the military, which is exactly what North Korea wants.
To restore stability, South Korea needs to rebuild its decision-making body. The parliament must reach a consensus on appointing a new minister of national defense. It’s essential that this new minister be a civilian to ensure the political neutrality of the armed forces and prevent groupthink in decision-making. Strengthening civilian control will ensure the military is not misused as a political tool to violate democratic principles. Furthermore, empty military command posts—left vacant after widespread convictions—need to be filled as soon as possible to restore order and confidence within the military.
Military readiness and deterrence through cohesive and predictable policy must take precedence over political bickering. South Korea must a develop a long-term security strategy—one that isn’t rewritten with each new government. Security must be viewed independently from domestic politics, and both the ruling and the opposition parties must set aside factional rivalries for national interest.
The opposition in particular needs to accept that working with Japan isn’t a choice—it’s a matter of survival, especially if US leadership diminishes. On this basis, the state council should build a broad consensus on security policy before the next administration takes office.
As regional threats grow, South Korea cannot afford to be stuck in internal divisions. South Korea’s survival depends on moving beyond partisan division and coming together to face the challenges ahead.