As 2025 draws to a close, China–Japan relations have sunk to their lowest point in decades, recasting Indo-Pacific security and hardening a loose China–Russia–North Korea alignment.
What began as historic animosity and territorial friction has become a daily test of wills. Around the Diaoyutai Islands, Chinese Coast Guard and maritime militia maintain a near-constant presence in the contiguous zone and make frequent incursions into Japanese waters. This gray-zone pressure challenges Japan’s administrative control and risks miscalculation.
Taiwan has moved to the center of Tokyo’s calculus. Senior officials now say Taiwan’s security is tied to Japan’s own. Defense white papers outline contingencies for a Taiwan crisis, including the defense of Japan’s southwestern islands. In response, the People’s Liberation Army has intensified drills around Taiwan, often uncomfortably close to Japanese territory — a pointed message to Tokyo.
Economic ties are also shifting from integration to “de-risking.” Beijing’s sustained ban on Japanese seafood after the Fukushima water release is widely seen as political coercion. In turn, Japan and G7 partners tightened controls on advanced semiconductor exports to China and are building supply chains that bypass Chinese dominance. Partial decoupling further erodes stability.
Japan’s military normalization is now in full swing. Guided by the 2022 National Security Strategy, Tokyo plans to double defense spending to 2% of GDP by 2027 and acquire long-range counterstrike capabilities. Tomahawk procurement and indigenous standoff missiles give Japan, for the first time since World War II, the means to hit targets deep inside an adversary’s territory.
Alliances have widened with this shift. Reciprocal Access Agreements with the United Kingdom and Australia enable joint exercises and logistics. Under US stewardship, ties with South Korea have thawed, producing real-time missile data sharing against North Korean threats. The result is a latticed network with Tokyo as a key node for integrated deterrence.
Adversaries are consolidating as well. China, Russia, and North Korea have tightened coordination, not through a formal treaty but a pragmatic alignment against the US-led order. Sino-Russian flotillas now conduct regular joint patrols around the Japanese archipelago through the Tsugaru and Soya straits, practicing complex operations aimed at Japan.
The war in Ukraine has accelerated this trend. Isolated by the West, Moscow leans on Beijing’s economic and diplomatic support and backs China’s stance on Taiwan while coordinating activity in the Pacific. North Korea, shielded at the UN by China and Russia, has pushed its missile and nuclear programs with impunity. Reports of munitions flowing to Russia in exchange for satellite and submarine technology alarm Tokyo and Seoul and fuel a cycle of action and reaction.
The net effect is an Indo-Pacific arms race. South Korea is investing in its three-axis defense system. Australia is acquiring nuclear-powered submarines under AUKUS. The Philippines is granting US forces greater access to bases facing the Taiwan Strait and the South China Sea. The risk that a clash in the East China Sea, the Taiwan Strait, or the Korean Peninsula could spiral is the highest in half a century.
Southeast Asian states face an unenviable dilemma. Economically tied to China yet wary of its expansion, they look to the US–Japan partnership for balance while striving to avoid stark choices. That tension threatens ASEAN unity and opens space for Beijing to expand influence. The post-Cold War balance has given way to a tense, unpredictable, and heavily armed standoff.
