The 65th anniversary of the Treaty of Friendship, Co-operation and Mutual Assistance between China and North Korea, commemorated during Xi Jinping’s state visit to Pyongyang on June 8-9, 2026, provides an occasion to examine how a Cold War alliance document signed on July 11, 1961 continues to shape one of the most strategically consequential bilateral relationships in Northeast Asia. The treaty, signed by Zhou Enlai and Kim Il Sung in an era when both China and North Korea were Soviet-aligned communist states competing with the US-led Western alliance and South Korea’s US-backed government, includes a mutual defense clause that has been interpreted as committing China to defend North Korea against external military attack – though the precise scope and conditionality of that commitment has been debated by legal scholars and strategic analysts for decades without authoritative resolution. What is not in doubt is that the treaty has provided the diplomatic and political framework within which China has consistently used its UN Security Council veto to prevent the harshest proposed international sanctions on North Korea’s nuclear and missile programs from being adopted, and within which Chinese economic support has prevented the Pyongyang government from facing the external financial pressure that could threaten its stability.

Xi’s decision to visit Pyongyang in June 2026 – less than three weeks after the Trump-Xi Beijing summit that represented the highest-level US-China diplomatic engagement of the period – reflects Beijing’s calculation that maintaining the China-North Korea relationship as a visible strategic partnership serves Chinese interests regardless of whether it creates diplomatic friction with Washington. For China, a stable North Korea that serves as a buffer against US military presence on China’s border, and that creates diplomatic leverage in China’s dealings with both Washington and Seoul, is worth the complications that North Korea’s nuclear and missile programs create for China’s international reputation as a responsible great power. The full account of Xi’s Pyongyang state visit covers the bilateral agreements and symbolic events of the June 8-9 meetings in detail, including Xi and Kim’s joint visit to the Sino-Korean Friendship Tower commemorating Chinese soldiers who died in the Korean War – the foundational sacrifice that both sides invoke to characterize the bilateral relationship’s depth.