South Korea's foreign affairs and presidential popularity

President Yoon Suk-yeol’s popularity has sharply declined since his election and it will soon impact foreign affairs.

President Yoon Suk-yeol’s popularity has sharply declined since his election in March 2022. Initially supported by 53% of the public, his approval ratings dropped due to controversial policies, including his push to expand medical school quotas, which led to a lengthy doctors' strike. The public’s dissatisfaction with his unilateral leadership style, economic challenges, and diplomatic performance further weakened his standing.

Yoon's positive rating is now at 27 percent. The previous record low was 29.3 percent in the first week of August 2022. The approval rating is now at its lowest level since he took office in May 2022

Yoon’s leadership approach remains a key factor in his ongoing unpopularity. This has an impact on foreign policy.

The president of South Korea plays a central role in the country’s foreign policy, with both constitutional powers and conventional responsibilities shaping the office's influence. As the head of state, chief executive, and commander-in-chief, the president is vested with broad authority to formulate and execute South Korea’s foreign relations, often in consultation with key advisors, government ministries, and institutional frameworks. These powers are codified in the Constitution and supplemented by long-standing political traditions.

The Constitution grants the president significant control over foreign policy. Article 66 designates the president as the protector of national sovereignty and security, inherently linking the office to foreign affairs. The president has the power to negotiate and ratify treaties, appoint ambassadors, and represent South Korea in international organizations. Furthermore, Article 73 gives the president the right to declare war, which further highlights the president’s central role in defense and foreign policy.

In matters of national security, the president can take direct command of the military, and in foreign policy, they can issue executive orders. Importantly, while the National Assembly must ratify treaties and international agreements, and approve key senior appointments, the president’s negotiation and initiation powers provide a commanding role in setting the foreign policy agenda.

This differs substantially from the U.S. where foreign policy powers are shared between the President and Congress. Article II, Section 2 of the U.S. Constitution gives the President the authority to make treaties (with Senate approval) and serve as Commander-in-Chief. Congress, under Article I, Section 8, holds powers such as declaring war, raising armies, and regulating foreign commerce. Unlike the U.S, the National Assembly cannot declare war, and its influence is largely indirect through budgetary oversight and treaty ratification. Thus, while the U.S. Congress has broader checks on executive foreign policy, the South Korean National Assembly’s powers are more constrained by its Constitution.

Beyond constitutional powers, the South Korean president follows traditions that define the conduct of foreign policy. Most prominent among these is the need for consensus. This means the President often consults with the National Assembly, opposition parties, and key stakeholders on major national issues such as foreign policy, economic reforms, and security matters.

For example, the President seeks prior legislative approval for major treaties, military deployments, and budget allocations before the bill is initiated. Although not a legal requirement in all cases, such consultations help ensure political consensus and democratic legitimacy in decision-making, especially in a divided National Assembly. The historical public distrust of “imperial presidency” requires that the presidential office is at least seen to seek consensus, even if consensus on specific issues are impossible.

The South Korean president is also supported by a robust advisory structure that helps shape foreign policy decisions. The National Security Council (NSC) serves as the main body for coordinating foreign and national security policy and advising the president on critical foreign policy matters, including relations with North Korea, defense strategies, and alliances. The Ministry of Foreign Affairs plays a secondary role, providing diplomatic expertise and implementing the president’s international agenda. 

Foreign policy advisors to the South Korean President are selected based on expertise, political and personal alignment, and experience in diplomacy, national security, or international relations. The President appoints key figures such as the Minister of Foreign Affairs, National Security Advisor, and senior aides from academia, government, or the military. Foreign policy influence can also be accrued through holding a strong public profile with the likelihood of appointment to key positions increasing with status and public recognition.

A decline in the South Korean president's popularity can significantly limit their powers in foreign policy through various mechanisms, both domestically and internationally.

Popularity often correlates with political capital—the ability to influence lawmakers and secure legislative approval. A president with waning public support may struggle to gain backing from the National Assembly, which plays a crucial role in ratifying treaties, approving budgets, and endorsing military actions. Opposition parties, sensing political vulnerability, are more likely to obstruct or delay foreign policy initiatives, making it harder to pass critical agreements or laws that support international engagement.

In South Korea’s democratic system, the president needs a strong mandate to govern effectively. A drop in approval ratings can undermine the president’s perceived legitimacy, prompting other political actors, including cabinet members, bureaucrats, or local governments, to resist or ignore foreign policy directives. Key foreign policy tools such as executive orders or military commands may face institutional push back, making swift action difficult.

As could be expected, weakened domestic support impacts the president’s international capacity. A president with declining popularity is perceived as politically weakened, reducing their credibility in negotiations. Foreign counterparts may question the president's ability to follow through on commitments, such as trade deals, security agreements, or peace talks. A president with diminished popularity may have less influence in global organizations like the United Nations or the G20. Weakened at home, they may find it harder to assert South Korea’s interests in multilateral forums, where domestic stability and strong leadership are key to wielding influence. 

Declining popularity after the midpoint of a presidential term also has a snowball effect. Senior officials and advisors who hold plans for their career in a future presidential administration start to “abandon ship”. They seek to exit the administration, and in certain circumstances, subtly criticize the administration, in order to strengthen their public profile for the next ideologically similar presidential administration, which must, in order to get elected, distance itself from the current administration. 

Yoon Suk-yeol’s declining domestic support has weakened his foreign policy leverage, both internationally and at home.

With approval ratings at historic lows, Yoon’s ability to negotiate effectively with foreign leaders, particularly on key (emotional) issues like North Korea and Japan, is diminished. Moreover, political opponents in South Korea have gained ground, limiting his mandate and capacity to push through foreign policy initiatives. His leadership’s lack of public backing also raises concerns among allies, reducing their confidence in his administration's stability and continuity in long-term partnerships.

Image: Office of the President of the Republic of Korea Website