Japan is entering a potentially historic political transition. Sanae Takaichi has won the leadership of the governing Liberal Democratic Party, placing her in position to become Japan’s first female prime minister and giving the country a leader whose politics differ substantially from the cautious managerial style associated with much of the post-war Japanese establishment. Takaichi is a committed conservative, an advocate of substantially stronger defence capabilities, a supporter of revising Japan’s pacifist constitution and a politician who has taken comparatively hawkish positions towards China while emphasising the importance of the alliance with the United States. Her rise comes at a moment when Japan faces an unusually difficult combination of strategic and economic pressures: China possesses far greater military power than it did twenty years ago, North Korea continues developing nuclear weapons and ballistic missiles, Russia’s invasion of Ukraine has weakened assumptions that major territorial war is impossible in advanced regions, Donald Trump’s return has created new uncertainty about the future terms of American alliance protection, and Japan’s own economy remains constrained by demographic ageing, enormous public debt and decades of relatively weak trend growth. Takaichi’s rise therefore should not be understood simply as Japan becoming more conservative. It reflects a much larger transformation in how Japanese policymakers increasingly understand the country’s place in the world. For most of the post-war era, Japan could maximise prosperity partly by minimising the role of military power in national strategy. The strategic environment is now making that bargain progressively harder to maintain.
Japan’s post-1945 political economy was built around an extraordinary institutional arrangement. Article 9 of the Japanese constitution renounced war as a sovereign right and prohibited maintaining traditional “war potential”, although Japan subsequently created the Self-Defense Forces and gradually developed one of the world’s most technologically sophisticated militaries. The United States provided the ultimate security guarantee, including nuclear deterrence, while Japan concentrated national resources on reconstruction, manufacturing, exports, infrastructure and technological development. This arrangement became associated with the Yoshida Doctrine, under which Japan accepted strategic dependence on Washington while prioritising economic recovery. The bargain worked exceptionally well. Japan transformed from a devastated wartime economy into the world’s second-largest economy by the late twentieth century without needing to finance military capabilities proportional to its economic size. American security therefore produced what economists might describe as a peace dividend multiplied over decades: resources that might otherwise have financed defence could support investment and household welfare while Japanese firms competed globally.
The success of this system can make its current transformation appear ideological when much of it is actually structural. China’s economy is now several times larger than Japan’s, the People’s Liberation Army has undergone enormous modernisation and Chinese naval and air activity around Japan has increased substantially. Beijing and Tokyo continue disputing sovereignty over the Senkaku/Diaoyu Islands in the East China Sea, while a Taiwan conflict would occur extremely close to Japan’s southwestern islands and American military bases on Japanese territory. North Korea possesses nuclear weapons and increasingly capable missiles capable of reaching Japan. Russia retains nuclear forces and territory disputed with Japan while maintaining a strategic partnership with China and deepening military cooperation with North Korea. Japan therefore sits geographically beside three nuclear-armed states, two of which are strategic competitors of the United States and one of which has repeatedly threatened neighbouring countries. Under those conditions, maintaining exactly the same defence posture designed during an earlier balance of power becomes increasingly difficult.
This is the security-environment endogeneity problem: a defence policy that appears sufficient under one distribution of power can become inadequate without the policy itself changing at all. Japan did not necessarily become more militaristic first; the region became more militarised around it. Chinese military expansion increases Japanese incentives to rearm, which Beijing then interprets as evidence of Japanese remilitarisation, strengthening China’s own justification for additional capability. The same security dilemma appears again. Each government describes its buildup as defensive while interpreting the other’s buildup as potentially offensive. Historical memory makes the cycle particularly sensitive because China and Korea experienced Japanese imperialism directly during the first half of the twentieth century. Japanese defence normalisation therefore carries a political meaning in neighbouring countries that equivalent military expansion elsewhere might not.
This is why constitutional revision remains so controversial. Article 9 is not merely a legal constraint. It became part of Japan’s post-war political identity, symbolising a rejection of the militarism that culminated in catastrophic war. Supporters of revision argue that a democratic Japan facing contemporary threats should possess the same normal defence rights as other sovereign states. Opponents fear that weakening constitutional constraints removes an important safeguard created precisely because Japanese institutions once allowed military power to escape civilian control. Both arguments therefore concern credible commitment across generations. The constitution was designed partly to reassure Japan’s neighbours and future Japanese citizens that the state would not return easily to military expansion. Revising it may increase contemporary defence flexibility while reducing some of that historical reassurance.
The institutional challenge is distinguishing normal military capability from revisionist military ambition. Japan can strengthen air defence, naval forces, cyber capabilities and long-range strike systems without seeking territorial expansion. Democratic civilian control, parliamentary oversight and alliance integration create constraints absent from imperial Japan. Treating every increase in Japanese defence spending as a return to 1930s militarism therefore ignores eighty years of institutional change. Yet historical memory should still impose caution because military institutions acquire bureaucratic interests like every other institution. Defence normalisation should occur through transparent democratic processes rather than through reinterpretations so gradual that constitutional restrictions lose meaning without voters ever confronting the change directly.
Takaichi’s politics places her near the assertive end of this debate. She has supported constitutional revision and a stronger military posture and has been associated with former prime minister Shinzo Abe’s conservative vision of Japan as a more “normal” strategic power. Abe began much of the transformation already. His government reinterpreted constitutional constraints to permit limited collective self-defence, strengthened the US-Japan alliance and promoted the concept of a Free and Open Indo-Pacific, which later became central to American and allied strategy. Japan’s current shift therefore did not begin with Takaichi. Her significance lies in potentially accelerating a trajectory that has been developing for more than a decade.
The Trump administration makes acceleration more rational because Japan now needs to consider alliance uncertainty alongside the external threat itself. The United States remains overwhelmingly committed institutionally to the US-Japan alliance, and American military bases in Japan make the relationship far deeper than ordinary diplomatic partnership. Yet Trump consistently argues that allies should contribute more financially to their own defence and has demonstrated willingness to use trade pressure even against strategic partners. Japan therefore cannot assume the terms of American protection will remain politically static forever. Like Europe, Tokyo has incentives to acquire greater autonomous capacity while preserving the alliance.
This produces the same credibility-burden-sharing paradox discussed around NATO. A perfectly credible American guarantee reduces Japan’s incentive to spend more on defence because Washington ultimately deters major threats. Greater uncertainty about the guarantee increases Japanese incentives to rearm. Trump can therefore strengthen allied burden-sharing precisely by making allies somewhat less certain about American protection. The danger is that if uncertainty becomes too large, allies may seek capabilities Washington does not want them to acquire.
For Japan, the ultimate example is nuclear weapons. Japan remains deeply committed publicly to non-proliferation and possesses the unique historical experience of Hiroshima and Nagasaki, making nuclear armament politically extraordinarily sensitive. Yet Japan also possesses advanced nuclear technology and the industrial capacity that could theoretically make a nuclear programme technically feasible if the political decision changed. If Japanese leaders ever concluded the American nuclear umbrella was no longer credible while China and North Korea remained nuclear-armed, domestic debate could shift dramatically. This is why American alliance credibility supports nuclear non-proliferation. Security guarantees are not simply protection for allies; they reduce allies’ incentives to acquire independent ultimate deterrents.
The same applies to South Korea, where public discussion of indigenous nuclear weapons has become increasingly visible. A world in which America demands much greater allied self-reliance but simultaneously reduces confidence in extended deterrence can therefore produce an unintended proliferation effect. The optimal American strategy is not making allies permanently dependent. It is encouraging stronger conventional capability while keeping the nuclear guarantee sufficiently credible that independent nuclearisation remains unnecessary.
Japan’s economic constraints make defence expansion particularly difficult because the country already possesses one of the highest public-debt-to-GDP ratios in the developed world, exceeding 200% of GDP by broad measures. Japan can sustain this partly because much of the debt is denominated in yen, domestic institutions hold large quantities and the Bank of Japan has historically maintained extremely low interest rates. But demographic ageing places increasing pressure on pensions and healthcare while the working-age population declines. Defence spending therefore competes with social expenditure at precisely the moment both are structurally rising.
This creates a much harder fiscal problem than Germany faces. Germany entered its current rearmament with comparatively low public debt. Japan begins with enormous accumulated liabilities. Every additional defence commitment therefore needs either higher taxes, spending restraint elsewhere, additional borrowing or stronger economic growth. Takaichi has historically favoured relatively expansionary fiscal and monetary policies associated with the legacy of Abenomics, making the arithmetic even more interesting. A government can support defence expansion and fiscal stimulus simultaneously in the short term. Over the long term, the economy’s productive capacity still determines how much real expenditure can be sustained without inflationary or debt pressure.
Japan’s demographic structure is therefore becoming a national-security variable. A shrinking working-age population means fewer taxpayers financing pensions and defence, fewer potential military personnel and fewer workers available for defence manufacturing. This is the same principle discussed in Europe: demography is slow-moving military power. A country can purchase advanced aircraft but still needs engineers to maintain them, workers to manufacture missiles and citizens to finance the state supporting them.
Japan has responded partly through automation and extraordinarily high capital intensity. Robotics can substitute for labour in manufacturing and increasingly in logistics and services. Defence systems themselves are becoming more autonomous, making Japan’s technological strengths particularly valuable. Drones, artificial intelligence, sensors, robotics and advanced materials can allow a country with demographic constraints to generate greater military capability per soldier. This creates a natural connection between industrial policy and defence policy.
Japan’s semiconductor strategy illustrates the broader transformation. Tokyo has committed large subsidies to rebuild advanced chip manufacturing, including support for TSMC’s plants in Kumamoto and the domestic Rapidus project. These policies are often described as economic nationalism, but they also reflect security concerns. Semiconductors sit inside automobiles, telecommunications, artificial intelligence and weapons systems. Taiwan currently plays an enormous role in advanced chip fabrication, meaning a conflict around Taiwan could create a global supply shock. Japan therefore is willing to pay an efficiency premium to locate more capacity domestically.
This is resilience as industrial insurance. The cheapest chip in peacetime is not necessarily the cheapest chip once geopolitical disruption risk is included. Governments therefore increasingly calculate expected cost rather than current market price alone. Japan, America, Europe, India and China are all applying versions of this logic, which is why the global semiconductor industry is becoming geographically more redundant and politically subsidised.
The economic danger is that every country labels the same industries strategic and subsidises them simultaneously, creating excess capacity and fiscal waste. Industrial policy therefore needs coordination among allies. Japan does not need complete semiconductor self-sufficiency if supply can be diversified across Japan, America, South Korea and Taiwan sufficiently that no single disruption becomes catastrophic. Resilience can be multinational. In fact, allied supply chains may be more efficient and strategically robust than national autarky.
This is where Japan’s relationship with South Korea becomes especially important. Historical disputes over Japanese colonial rule have repeatedly damaged bilateral relations even though both countries face North Korean missiles and Chinese strategic power while relying on the United States. From a pure security perspective, Japan and South Korea should cooperate extensively. Historical memory makes that politically difficult. This is another example of identity imposing transaction costs on strategic cooperation. The underlying threat does not erase historical grievance.
A Takaichi government could complicate this further because her conservative historical positions and visits or potential visits to Yasukuni Shrine, where Japan’s war dead including convicted war criminals are commemorated, are highly controversial in China and South Korea. Domestically, supporters can view such acts as ordinary respect for national war dead and resistance to permanent external judgement of Japanese history. Abroad, they are interpreted through memories of imperial occupation. The same symbolic action therefore possesses radically different political meanings depending on the audience.
This matters strategically because symbolism can consume diplomatic capital that Japan needs for practical security cooperation. A government can believe its historical interpretation is justified while still asking whether a symbolic act produces enough domestic benefit to justify deterioration in relationships with countries essential to regional balancing. Political leaders need not concede historical arguments to recognise their opportunity cost.
China would benefit strategically from severe Japan-South Korea tensions because it weakens American alliance coordination in East Asia. Japan therefore should avoid giving Beijing inexpensive opportunities to exploit historical divisions. South Korea has the same responsibility. Historical accountability and strategic cooperation do not need to be mutually exclusive if institutions allow disputes to remain compartmentalised.
Taiwan will probably remain the largest security issue. Japan’s southwestern islands sit close to Taiwan, American bases in Japan would almost certainly become relevant to any major US intervention and disruption of Taiwan Strait shipping would affect Japan’s economy immediately. Tokyo therefore cannot treat Taiwan as a distant Chinese domestic question in purely practical terms, regardless of its formal diplomatic position.
At the same time, explicit Japanese commitments to fight for Taiwan could increase Chinese threat perceptions and reduce diplomatic flexibility. Japan therefore benefits from strategic ambiguity combined with visible capability. China should believe a Taiwan conflict could involve substantial Japanese support for America without Tokyo necessarily specifying every trigger publicly. Deterrence often works through uncertainty when the adversary fears a broader response than the defender has formally promised.
The economic relationship with China complicates this because China remains one of Japan’s largest trading partners. Japanese companies depend on Chinese demand and manufacturing networks even while the Japanese government increasingly regards Chinese military power as its principal long-term strategic concern. This is the defining contradiction of contemporary Asian geopolitics: the countries most worried about one another militarily can remain deeply integrated economically.
Complete decoupling would impose enormous costs. Complete dependence creates strategic vulnerability. Japan therefore is pursuing de-risking, diversifying selected supply chains while maintaining broad trade. This is probably more sustainable than attempting total separation. The policy challenge is identifying which dependencies are genuinely dangerous rather than allowing national-security logic to spread across every commercial sector.
Japan’s relationship with India becomes increasingly important inside this architecture. Both countries participate in the Quad, both worry about Chinese regional dominance, both support a rules-based maritime order and both possess incentives to diversify supply chains. India provides scale, labour and Indian Ocean geography. Japan provides capital, technology and infrastructure expertise. Their economic complementarities therefore reinforce strategic cooperation.
Projects such as the Mumbai-Ahmedabad high-speed rail corridor, despite delays and cost debates, represent a larger pattern of Japanese investment in Indian infrastructure and manufacturing. As companies seek alternatives to excessive China concentration, India can become more important to Japanese supply chains. This creates another form of economic balancing: strategic partnerships become more durable when businesses and infrastructure create constituencies benefiting from them.
Takaichi’s rise could therefore strengthen India-Japan relations even if her domestic conservatism generates controversy elsewhere. Japan’s desire for stronger regional partners aligns with India’s desire for strategic autonomy and greater investment. Neither country wants a formal anti-China alliance requiring automatic military commitments. Both benefit from increasing the number of constraints China faces if it attempts regional domination.
This is balancing without bloc formation, something increasingly characteristic of the Indo-Pacific.
The domestic symbolism of Japan potentially receiving its first female prime minister is also complicated. Takaichi’s gender represents a historic breakthrough in a country that has long ranked poorly among advanced economies in women’s political representation. Yet her policy positions are not conventionally associated with feminist politics, and she has taken conservative positions on several social questions. This illustrates why descriptive and substantive representation are different. A woman occupying the highest office changes who can visibly hold political power. It does not mean her policy agenda represents all women or advances every policy associated with gender equality.
That distinction is important because identity-based political analysis often assumes representatives automatically embody the preferences of demographic groups they belong to. They do not. Representation can change symbolism without eliminating ideological diversity inside the represented group. Japan can therefore experience a major milestone in women’s political leadership while simultaneously electing one of its more socially conservative leaders.
Takaichi’s larger challenge will be converting political symbolism and security rhetoric into effective government. Japan’s economic problems are not principally caused by insufficient nationalism. Productivity growth in services remains weak relative to some peers, the population is shrinking, wages have struggled for decades to produce sustained real gains and public finances remain strained. Defence expansion cannot substitute for economic reform.
The government therefore needs to improve labour-force participation, encourage productivity-enhancing investment, manage immigration more effectively, support families without assuming subsidies alone can reverse fertility decline and maintain technological competitiveness. None produces immediate political drama. Together they determine whether Japan possesses the economic base required for the stronger strategic role Takaichi advocates.
This is the fundamental relationship between economic power and military ambition. A country can increase defence spending rapidly through borrowing. Sustaining greater military power for thirty years requires a productive economy capable of financing it. Imperial Japan itself ultimately demonstrated the danger of strategic ambitions exceeding the resource base available to support them, although contemporary democratic Japan is obviously an entirely different political system. The general principle remains: strategy needs to match national capacity.
Japan’s transition therefore should be measured not by whether defence spending reaches a particular percentage of GDP or whether Article 9 is revised. Those are inputs and institutional choices. The important outcomes are whether Japan becomes more difficult to coerce, whether alliance burden-sharing becomes more sustainable, whether regional partners trust Japanese intentions and whether greater security expenditure occurs without undermining long-term fiscal stability.
A successful Japanese normalisation would produce a country capable of defending itself more substantially while remaining deeply embedded in democratic alliances and regional economic institutions. An unsuccessful version would produce expensive military expansion, deteriorating relationships with neighbours and fiscal pressure without significantly improving deterrence.
The distinction depends heavily on diplomacy. Power becomes safer when institutions make its purpose predictable. Japan should therefore combine rearmament with transparency, crisis communication with China and deeper cooperation with South Korea, India, Australia and the United States. Military capability and diplomatic reassurance are complements rather than alternatives.
This is the lesson of every security dilemma discussed this year. If one country increases military power without communicating limits, neighbours respond according to worst-case assumptions. If reassurance exists without capability, adversaries may discount it as weakness. Stable deterrence requires enough strength to prevent aggression and enough predictability to prevent that strength from appearing offensive.
Japan spent much of the post-war era relying disproportionately on the second half of that equation because America supplied much of the first. The strategic environment is now forcing Japan to supply more of both itself.
That transformation would probably have occurred regardless of who led the LDP. Takaichi may accelerate it and give it a more explicitly nationalist political language. Her historical significance therefore may extend beyond becoming Japan’s first female leader.
She could preside overthe transition from a Japan whose post-war identity was built partly around the restraint of national power towards one that increasingly believes preserving the post-war order requires possessing considerably more power of its own. The paradox is striking. Japan may need to move beyond parts of its post-war security model precisely because it wants to preserve the peace and prosperity that model helped create.
