Japan’s Paradigm Shift on Wartime Independence

The Indo-Pacific faces escalating tensions, with Japan at the heart of potential conflicts. Tokyo’s military revival and diplomatic maneuvers highlight the stakes of regional security and alliance uncertainty.

The Indo-Pacific is a hotspot where armed conflicts could occur along the Taiwan Strait (19FortyFive, 2025), the Korean Peninsula (Modern Diplomacy, 2025), and the South China Sea (19FortyFive, 2025). Japan is caught in the middle of the Taiwan Strait and South China Sea conflicts. Tokyo’s economic and maritime shipping lanes would be threatened if the situation becomes unfavorable (E-International Relations, 2025).

During a parliamentary session, Taro Yamamoto, a left-wing populist politician in Japan, raised the possibility that the Japanese Self-Defence Forces (JSDF) could fall under United States command in the event of a major war in the Asia-Pacific region (Yamamoto, 2023).

Though independent since the early 1970s, Japan has relied on U.S. defence (International Crisis Group, 2023). It has also made strides toward military reawakening since the early 2020s. Still, a recent diplomatic spat over a Taiwan contingency has brought Tokyo and Beijing into a conflict not seen since the East China Sea provocations (USNI News, 2016).

Japan’s Military Awakening and New Foreign Policy Approach

Under Shinzo Abe, the Japanese Self-Defence Forces (JSDF) gradually rebuilt their capabilities to confront rising threats from China and North Korea (Geopolitical Futures, 2024). Against the backdrop of Russia’s invasion of Ukraine, Tokyo allocated one of the world’s largest defence budgets to continue enhancing the capabilities of the JSDF into a full-fledged military (E-International Relations, 2025).

Despite pledges and rising defence spending, Japan has experienced successive short-term governments and prime ministers. Instability has plagued the ruling Liberal Democratic Party (LDP) (BBC News, 2024). Economic stagnation, a major demographic crisis, and trade imbalances with the United States have fueled internal conflicts and eroded confidence (Japan Society, 2023).

Nevertheless, Japan continues its remilitarization efforts. These include enhancing the navy (JMSDF) with upgraded Tomahawk missiles (USNI News, 2025) and upgrading its missile defence system (Asia Times, 2025). The goal is to counter North Korea, China, and Russia. Japan is also deepening defensive pacts with the Philippines and Taiwan.

Sanae Takaichi, veering from the closed-door, ambiguous policies of former LDP prime ministers, took a major step. Takaichi declared a Taiwan contingency existential to Japan, which could allow the JSDF and JMSDF to intervene directly if Taipei is threatened (Asia Times, 2025).

This shift in policy has triggered notable diplomatic objections from China (Nippon.com, 2024). The Trump Administration, despite the Japanese prime minister’s alignment with the MAGA movement, has yet to provide full support for Takaichi’s approach (Financial Times, 2024).

Does the U.S. Have Command Over the JSDF?

After Japan’s unconditional surrender, the United States directly commanded the JSDF. Article 9 of the American-written Japanese constitution blocked full remilitarization (Archives Foundation, 1945). In 1952, Japan regained independence and reclaimed control over the JSDF as American oversight faded (National Library of Australia, 1952).

Despite Tokyo’s full control over the Self-Defence Forces, Article 9 limits Japan’s ability to fully militarize (SIPRI, 2023). To address these defense gaps, U.S. Forces Japan (USFJ) continuously trains and upgrades the JSDF’s capabilities.

A March 2025 Stimson Center article reported that the U.S. intends to support Japan with American offensive capabilities if Tokyo faces a defensive war, such as a conflict with the Chinese military (PLA) and naval forces (PLAN) in the East China Sea (Stimson Center, 2025). However, the publication notes U.S. concerns about Japan striking enemy territory offensively without American coordination.

A scenario in which Japan could now intervene militarily in a Taiwan contingency is one for which the U.S. could recalibrate. If China were to strike JSDF military bases and key command centers in Japan without drawing in USFJ or direct American intervention, Tokyo could retaliate on the Chinese mainland. This would cause concern in Washington—especially given the ongoing Trump Administration’s peace agenda (Atlantic Council, 2024).

According to the Financial Times, the Trump Administration has quietly told Prime Minister Takaichi to lower rhetoric on a Taiwan contingency (Financial Times, 2024). Washington seeks to secure a major trade agreement with Beijing, even if it comes at the expense of Taipei and Tokyo. By sidestepping a close alliance, the U.S. could hypothetically limit offensive military capabilities provided to the JSDF. American policymakers believe these could be used in a war against China.

Examining Myths and Facts Over the Post-WWII-Remilitarization

A key factor in the confusion over potential USFJ control over the JSDF is the scope of remilitarization Washington could grant to Tokyo. As mentioned, Japan could find itself alone if the current U.S. administration and National Security Strategy isolate traditional allies and become more isolationist; this would effectively give China a window to strike.

Japan’s maritime imports and exports pass through various seas that the PLAN could control if Taiwan falls. Tokyo’s economy would be strangled, and a state of vassalage could result if China succeeds.

Facing a potential national emergency in the First Island Chain, Tokyo recognizes that the JSDF and JMSDF will require greater autonomy. Without robust and explicit USFJ support, Article 9 of the American-written constitution could bind Japan’s options.

Article 9 allows the JSDF to maintain a strong defensive force for Japan. If a Taiwan contingency takes place without the USFJ, Tokyo would need to go on the offensive. This presents a crossroads. There is a fear that a more isolationist or unorthodox U.S. administration may not give Japan the offensive capabilities needed to protect maritime space, Taiwan, and Japanese citizens.

Due to these constraints, Tokyo will continue working to help America understand Japan’s precarious position in the turbulent Indo-Pacific region. If Japan’s sovereignty is threatened without concrete U.S. support, a push for nuclear proliferation could grow (E-International Relations, 2025).

Overall, U.S. Forces Japan does not have full control over the JSDF, but if a growing isolationist or spheres-of-influence American government does not fully back Taipei or Tokyo’s ‘Taiwan contingency,’ Washington could limit offensive weaponry to Tokyo if Japan finds itself alone in another Strait Crisis.

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