Why did the 21st century start on 20 January 2025?
History doesn’t follow a calendar. It surges in moments when old systems fracture and new ones erupt. 20 January 2025 was such a moment. Two events—Donald Trump’s divisive return to power and the seismic release of DeepSeek, a Chinese open-source AI—collided to bury the “long 20th century” and ignite a new epoch. Here’s why.
The end of the ‘Long 20th century.’
Historians measure time not in dates but in ideas. The “long 19th century” began with the French Revolution (1789) and ended with World War I (1914). Similarly, the “long 20th century” began in 1917, when the U.S. entered World War I and emerged as a global power. That era ended in 2025.
Two forces drove this rupture:
1. Trump’s inauguration: The collapse of the American order
Trump’s return to power marked more than a political shift—the symbolic end of a century defined by U.S. global leadership. Since 1917, America has shaped international institutions, alliances, and liberal ideals. Trump’s “America First” agenda—prioritizing nationalism over globalism and economic protectionism over cooperation—shattered that legacy.
But the change ran deeper. Trust in shared truths—science and facts—collapsed. Social media and partisan media turned public discourse into a battlefield of competing narratives. This “epistemic rupture” mirrored the Enlightenment’s clash with absolutism in 1789. Governance is no longer about policy; it’s about controlling reality itself.
2. DeepSeek’s launch: The rise of cognitive capitalism
On the day of Trump’s inauguration, DeepSeek released a powerful open-source AI model. Unlike Silicon Valley’s proprietary systems, DeepSeek’s code was free to all—a direct challenge to Big Tech’s dominance.
This wasn’t just a tech breakthrough. It signalled a shift from industrial capitalism (powered by money and machines) to cognitive capitalism (fueled by knowledge and creativity).
DeepSeek proved innovation no longer requires vast wealth—just ingenuity. China, once a tech imitator, now leads a new arms race: not for control of data or chips, but for dominance over ideas and narratives.
The new era’s DNA: Fracture and innovation
Together, these events define the 21st century:
- Political fragmentation: The post-1945 rules-based order is dead. Nations now prioritize self-interest over alliances, turning diplomacy into transactional bargaining.
- Techno-cognitive revolution: Power flows from algorithms, not oil. Open-source AI democratizes innovation but risks chaos as control slips from traditional gatekeepers.
Marc Andreessen called this a “Sputnik moment.” The “long 20th century” collapsed under its own flaws—globalization’s inequities, institutional decay, and the weaponization of truth. What emerges is an age of volatility, creativity, and reinvention.
The new century starts
The 21st century didn’t begin in 2000. It began on 20 January 2025, when the old world finally gave way. The question is no longer if we adapt but how.
- Will AI unite or divide us?
- Will nationalism fracture societies, or can new convergences emerge?
What is a “long century”?
The idea of a “long century” aligns with historian Fernand Braudel’s framework of historical time:
Longue durée: Slow-moving forces like geography, climate, and social systems that shape history over centuries.
Conjonctures: Medium-term cycles, such as economic trends or demographic shifts, unfolding over decades.
Événements: Short-term events like wars or revolutions are often surface-level and must be understood within deeper structural contexts.
Braudel argued that true historical insight comes from focusing on the longue durée and conjonctures—the enduring forces that give meaning to the chaos of events. The “long century” is a lens to see how these forces collide, defining eras and reshaping the world.
What is America’s ‘long century’?
America’s ‘long century’ origins can be traced back to 16 January 1917. That day, The New York Times published the Zimmermann Telegram, a secret message from Berlin to Mexico City proposing an alliance: if Mexico joined Germany in World War I, it would regain territories like California and the southwestern U.S.
The British intelligence operation that exposed the telegram sparked public outrage, pushing Congress to end the isolation policy and declare war on Germany. The U.S. embraced a global mission from that moment, shaping international institutions, alliances, and liberal ideals for over a century.
Trump’s presidency marked the end of this era. While the U.S. will remain active globally, it is no longer its priority. The new administration shifted focus to a national agenda, economic protectionism, and scepticism toward global institutions.
This move symbolically dismantled the liberal international order the U.S. championed since the founding of the United Nations. The “long American century” is over, and the world is grappling with what comes next.
The idea of a ‘long century’ isn’t tied to calendar dates but to transformative socio-political and cultural cycles. For example, the “long 19th century” began with the French Revolution in 1789 and ended with World War I in 1914. Similarly, the ‘long 20th century’ started in 1917, when the U.S. entered global politics and ended in 2025 with the dual shocks of Trump’s presidency and the rise of AI.
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