Iran war strengthens Japan’s push for rearmament

As tensions in the Middle East escalate, heightening global security risks, Japanese Prime Minister Sanae Takaichi is accelerating revisions to three key national security documents, aiming to fully strengthen Japan’s defensive deterrence through AI-driven combat strategies and a concrete “counterstrike capability”.

On 3 March, at a House of Representatives Budget Committee meeting, Takaichi emphasised that Japan must advance its defence measures with greater urgency, adding that no country lacking the resolve to defend itself can expect others to come to its aid.

The Takaichi administration plans to set up an expert panel in April to begin the revision process, aiming to complete the proposals by the end of this year.

Following her decisive election victory in early February, Takaichi had already announced in her policy speech that the three security documents would be revised ahead of schedule this year. Now, the Middle East conflict is seen by the ruling Liberal Democratic Party (LDP) as a catalyst to accelerate the process further.

Japan’s three security documents — the National Security Strategy, which sets out long-term security policy; the National Defense Strategy, which defines defence objectives and how to achieve them; and the Defense Buildup Program, revised every five years — were last updated four years ago under Prime Minister Fumio Kishida. China was identified as Japan’s “greatest strategic challenge”, and North Korea and Russia as “threats”. At the time, Kishida warned that “Ukraine today may be East Asia tomorrow”.

In the version revised four years ago, “counterstrike capability” was one of the most prominent keywords, referring primarily to Japan’s ability to strike targets such as enemy missile launch sites when an attack is imminent.

According to Nikkei, the new security documents will further specify this concept, clearly defining the forces tasked with executing counterstrikes. They also plan to include the long-range counterattack missiles being deployed this year, highlighting Japan’s systematic efforts to strengthen its deterrence.

In addition, revisions to the National Security Strategy will focus on responding to “new forms of warfare”. Japan intends to incorporate high-tech combat concepts into the document, taking cues from the US military’s recent use of AI to rapidly identify numerous targets in operations in Iran. In response to threats from drone swarms, the defence ministry is developing electromagnetic interference systems and plans to strengthen defence mechanisms against information warfare and disinformation.

A former senior official of the Japan Self-Defense Forces (SDF) believes the revision is likely to push the government to establish closer cooperation with private companies: not only to jointly build a defence industry supply chain, but also to strengthen collaboration on cyber defence and responses to cyberwarfare.

When the three security documents were revised four years ago, the Japanese government set a defence spending target of 43 trillion yen (US$302 billion) for 2023-2027. However, with persistent inflation and a weakening yen, this budget may not be enough to meet the original target. Observers expect that the new documents could further increase the budget to narrow the gap with China’s military capabilities.

Notably, the Takaichi administration could use the revisions to adjust Japan’s longstanding “three non‑nuclear principles” — not possessing, producing or permitting the introduction of nuclear weapons. In a Diet speech in November 2025, Takaichi said she could not guarantee that the new National Security Strategy would continue to state these principles explicitly. In addition, a highly valued senior security official in the Prime Minister’s Office stated when interviewed by the media anonymously in December 2025 that he supported Japan acquiring nuclear weapons.

Many within the ruling party see the situation in the Middle East as a catalyst for revising Japan’s security documents. An LDP official said, “When people see an actual war, they naturally develop a strong sense of crisis and a desire to defend the country. We will gain greater support for revising our security policy.”

Looking back at Japan’s post-war security policy, the 1990s Gulf War was a watershed. Although the pacifist constitution still made overseas deployments controversial, the government sent SDF personnel to the Gulf for minesweeping for the first time, under the banner of “international contribution”. From then on, Japan’s role in international military cooperation has shifted from financial contributions to taking on military responsibilities.

In 1997, Japan revised the Guidelines for Japan-US Defence Cooperation for “situations in areas surrounding Japan”, and in 2015 it went further by passing new security legislation that allows the SDF to support the US more actively within the alliance framework.

With each revision of Japan’s security strategy, it gradually chips away at the pacifist constitution’s restrictions on the use of force. The constitution currently imposes strict limits on SDF’s involvement in overseas conflicts. To remove this institutional obstacle, the LDP has long advocated constitutional revision, proposing to write the SDF explicitly into the constitution and to redefine Japan as a “normal country”.

University of Tokyo Professor Emeritus Haruki Wada told Lianhe Zaobao that within the framework of the Japan-US alliance, it is difficult for Japan to break away from following Washington’s lead. The recent US military action against Iran has also left Japan in a passive position. He said, “Behind the push to strengthen security is a fear that a security vacuum could emerge in East Asia. If the situation in the Middle East continues to deteriorate, it could disrupt the balance of power in East Asia.”

Some Japanese defence officials pointed out that the US currently has two aircraft carriers deployed in the Middle East, and that Japan must reassess its defence policy on the basis that US deterrent power in East Asia has been partially diverted.

Tetsuya Takahashi, a professor at University of Tokyo, puts it bluntly: “A world war is brewing.” He noted that two out of the three major regions of Eastern Europe, the Middle East and East Asia are already at war. 

He added, “If conflict also breaks out in East Asia, the linkage of all three could escalate into a world war.”

After 30 years of economic stagnation, Japan’s overall economic strength is no longer what it was. Yet the Takaichi administration is seeking to harness public anxiety over two ongoing wars to push for a more proactive security strategy, as well as to break through the constraints of the pacifist constitution. In doing so, Takaichi would have to face not just the risk of worsening the regional security environment, but also contend with far tighter fiscal and economic constraints.

This article was first published in Lianhe Zaobao as “应对中东战火与东亚局势 日本修订安保文件通过AI强化威慑力”.

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