270-Year Cycle — Deep Analysis

The Modern Ōnin War (Middle East Conflicts) Has Begun
— What the 270-Year Cycle Tells Us About the Next 100 Years

The Middle East conflicts are the modern Ōnin War. From chaos to new order: 83–150 years — what the 270-year cycle tells us about the next 100 years.

Hiroshi Yamada / White & Green Co., Ltd. | March 2026 | white-green.jp/en

What Was the Ōnin War? Historical Background and Its Impact on Japan

The Ōnin War (1467–1477) was a civil conflict that erupted from a succession dispute within the Ashikaga shogunate — Japan’s ruling military government. Two great rival factions, the Eastern Army (Hosokawa Katsumoto) and the Western Army (Yamana Sōzen), clashed for supremacy, and their battlefield was Kyoto itself. The capital burned for a decade. But the Ōnin War was not merely a power struggle: it was the event that announced the end of Japan’s unipolar order under the shogunate.

Japan before the war — the Muromachi shogunate

The Ashikaga (Muromachi) shogunate (established 1336) maintained a centralized hierarchy with the shogun at its apex, exercising control over regional military governors across Japan. Culturally, it was a remarkable era — the golden and silver pavilions (Kinkaku-ji, Ginkaku-ji) symbolized the flourishing of the Kitayama and Higashiyama cultural traditions, which gave birth to Noh theater, the tea ceremony, and ink-wash painting. These arts remain at the core of Japanese culture today. Though the shogun’s authority was never absolute, a workable order prevailed.

What the war changed — the age of “the low overcoming the high”

A decade of warfare destroyed the shogunate’s authority completely. The shogun became a figurehead, and regional lords began expanding their domains independently in what became known as the Sengoku period — the “Warring States” era. The social value of gekokujō (“those below overturning those above”) pervaded Japanese society: peasants defeated samurai, retainers overthrew their lords. Over 100 regional powers competed for supremacy simultaneously.

The 148 years that followed — from Nobunaga to the Edo shogunate

The chaos of the Ōnin War era ended only with Oda Nobunaga (1534–1582). In 1573, Nobunaga expelled the last Ashikaga shogun, Yoshiaki, delivering the institutional death blow to the old order. Power then passed to Toyotomi Hideyoshi and finally to Tokugawa Ieyasu, whose victory at the Battle of Sekigahara (1600) secured hegemony. The new order was consolidated at the Siege of Osaka in 1615. From the Ōnin War to stable Edo rule: 148 years — the time required to move from the collapse of the old order to the establishment of the new.

Section 1: Current Position — Two Zero Deviations

Quantitative analysis under the 270-Year Civilization Cycle Theory (Yamada, 2026) has confirmed two independent zero-deviation transition points simultaneously approaching for the United States.

Section 2: The Ōnin War Model — History’s Pattern After Unipolar Collapse

The critical point: the people living through the Ōnin War did not know that “Nobunaga will come.” They could not even see when the chaos would end. The same is true now. The next “Nobunaga” is almost certainly still in the periphery — or not yet born.

Section 3: War Patterns in Multipolar Transitions — Not One Big War

The assumption that “transition to multipolarity = World War III” is historically inaccurate. The war pattern in multipolar transition periods is not “one large confirmation war” but “multiple simultaneous medium-scale wars, prolonged and unresolved.”

As of 2026, this has already begun: Ukraine, Gaza, Lebanon, Iran, the Taiwan Strait, the Korean Peninsula — regional versions of the “Ōnin War” erupting simultaneously. One important historical counter-example exists: the pre-colonial Indian Ocean (1st–15th centuries) maintained a peaceful multipolar order through shared rules (maritime law, trade customs) without any hegemonic power. “Multipolarity does not necessarily mean war” — but achieving this in the current geopolitical environment is extremely difficult.

Section 4: Nuclear Deterrence Collapse — “Nuclear War Would Not End Humanity”

The Numbers

The world currently holds approximately 12,500 nuclear warheads. If all were used against major cities, estimated casualties would be:

70–80% of humanity survives. What does this mean? Nuclear deterrence has functioned for 70 years on the basis of emotional fear — “use it and the world ends.” The moment that shifts to rational calculation — “use it and the world doesn’t end; my side survives” — nuclear weapons are downgraded from “unusable” to “usable.”

When these three premises collapse

The current Middle East situation is a region where all three premises are fragile. Israel is a nuclear power (estimated 80–400 warheads) in effective warfare with Gaza, Lebanon, and Iran simultaneously. The premise that “possessing nuclear weapons prevents attack” has already broken down. The next question is whether they will be used.

Israel’s security doctrine includes the “Samson Option” — the unofficial posture that nuclear use is not off the table when facing existential threat. The moment Iran approaches operational nuclear capability, or the moment Israel is cornered in conventional warfare, this option becomes a real choice.

Section 5: The Post-Nuclear World and the “Next Nobunaga”

In the post-nuclear-use world, the 270-year cycle’s “law of peripherality” becomes decisive. History consistently shows that the next hegemonic actor emerges from the periphery of the existing order. The next “Nobunaga” in the post-nuclear world will be whoever can answer: “How do we rebuild order after nuclear use?”

The greater the destruction, the faster the transition to new order — paradoxically. The post-WWII institutions (UN, Bretton Woods, NPT) emerged directly from the most catastrophic war in history. The designer of that new order — the United States — gained 70 years of hegemony. The same principle will apply after the next catastrophic event.

Section 6: Three Scenarios for 2025–2200

Conclusion: Living Inside the Ōnin War

The people of Kyoto living through the Ōnin War (1467–1477) did not know that “Nobunaga will end this in 106 years.” They could only see today’s food and tomorrow’s safety. The same is true now. From the 270-year cycle, we can see that “we are inside the Ōnin War” — but we cannot know who the next Nobunaga is, or when they will appear.

The 270-year cycle offers two certainties: first, the chaos will end — it always has. Second, the next Nobunaga will come from the periphery — almost certainly not from China, the US, or the EU as currently constituted. The design for the next 270 years exists somewhere among forces and principles that, in 2026, no one is paying attention to.

In 1467, no one predicted that a minor lord from Owari province would unify Japan.

Update — March 28, 2026: Iran’s NPT exit bill emerges

The two mechanisms this article described — the collapse of nuclear deterrence and the emergence of new governing principles from the periphery of the existing order — are unfolding simultaneously on the day of publication. Iran’s move to exit the NPT framework and build new rules with the SCO/BRICS bloc is structurally identical to what happened after the Ōnin War: the collapse of the old order and the search for a new organizing principle from outside the existing center.

The nuclear taboo has not yet been broken. But today’s developments represent the institutional groundwork being laid for that possibility.

Source: Al Jazeera — As war rages, Iranian politicians push for exit from nuclear weapons treaty (March 28, 2026)

This paper presents historical analysis based on the Triple Cycle Theory and does not constitute a prediction of specific future events. Scenarios involving nuclear use are theoretical and historical analysis, not advocacy for any political position.
Related paper: OSF Preprints — Do Hegemonic Transition Cycles Align with the 270-Year Civilization Cycle? | white-green.jp/en