Whether watching international news or reading historical stories, it seems that every time a new power emerges rapidly, the ruling hegemon begins to worry, and the relationship between the two deteriorates rapidly.
The ancient Greek historian Thucydides said 2,500 years ago:
The rise of Athens and the fear that this instilled in Sparta made war inevitable.
Today, this statement has become one of the most important keys to understanding contemporary international relations: the “Thucydides Trap”.
Why Are the Hegemon and the Challenger Always at Loggerheads?
Imagine you are a student who has always ranked first in class. One day, a transfer student arrives, closing the gap in grades every time and progressing at a breakneck speed.
What would you think?
“Is he trying to take my spot?”
This is the core of the “Thucydides Trap”.
The Thucydides Trap is an international relations theory proposed by Harvard University scholar Graham Allison, describing a recurring historical pattern:
When a rising power threatens the position of a ruling power, war is highly likely.
This is also a classic case of the Security Dilemma. Wars often occur not because both sides truly desire to fight, but because three forces are intertwined:
| Driver | Description |
|---|---|
| Fear of the ruling power | The hegemon worries that the challenger will seize its leadership position and interests |
| Self-confidence of the rising power | As its strength grows, the challenger begins to demand a greater voice and sphere of influence |
| Structural pressure | Friction in security and economy intensifies, leading to potential miscalculations or being dragged into war by third-party conflicts |
What Does a War in Ancient Greece 2,500 Years Ago Have to Do with Us?
In ancient Greece 2,500 years ago, there were two superpowers in the Mediterranean world:
| State | Role |
|---|---|
| Sparta | Land hegemon (Hegemon) |
| Athens | Rapidly rising through trade and navy (Challenger) |
As Athens grew stronger, Sparta became increasingly anxious. Thucydides wrote in his record of this history:
“The rise of Athens and the fear that this instilled in Sparta made war inevitable.”
Eventually, the two sides fought the Peloponnesian War, resulting in a lose-lose outcome, with the entire ancient Greek civilization declining together.
In 2012, Graham Allison formally introduced the term “Thucydides Trap” in a Financial Times article discussing potential conflicts between the US and China.
16 Historical Cases of the Thucydides Trap Over 500 Years
Over the past 500 years of human history, there have been a total of 16 cases of power transition that fit the “hegemon meets challenger” scenario.
This historical record is tragic: out of 16 power transitions, 12 led to all-out war, and only 4 were successfully avoided peacefully.
| Period | Ruling Power (Hegemon) | Rising Power (Challenger) | Outcome |
|---|---|---|---|
| Late 15th Century | Portugal | Spain | Peace, Pope intervened to draw the line, signing a treaty to divide the New World |
| First Half of 16th Century | France | Spain | War, Italian Wars broke out, France suffered a crushing defeat |
| 16th-17th Century | Spain | Ottoman Empire | War, fighting for control of the Mediterranean, Battle of Lepanto |
| First Half of 17th Century | Spain | Sweden | War, Thirty Years’ War, shattering Spain’s European hegemony |
| Mid-to-Late 17th Century | Netherlands | Great Britain | War, three Anglo-Dutch Wars, Britain seized the monopoly of maritime trade |
| Late 17th to Mid-18th Century | France | Great Britain | War, all-out conflict in Europe and overseas colonies |
| Late 18th to Early 19th Century | Great Britain | France | War, Napoleonic Wars, France defeated |
| Mid-19th Century | Great Britain, France | Russia | War, Crimean War, Russia was pushed back |
| Mid-19th Century | France | Germany (Prussia) | War, Franco-Prussian War, France ceded territory and paid reparations |
| Late 19th to Early 20th Century | China (Qing Dynasty), Russia | Japan | War, Sino-Japanese War and Russo-Japanese War |
| Early 20th Century | Great Britain | United States | Peace, Britain recognized reality, chose to back down, and peacefully transferred hegemony |
| Early 20th Century | Great Britain (plus France, Russia) | Germany | War, World War I |
| Mid-20th Century | Soviet Union, France, Great Britain | Germany | War, World War II |
| Mid-20th Century | United States | Japan | War, Japan’s surprise attack on Pearl Harbor, Pacific War |
| 1940s-1980s | United States | Soviet Union | Peace, nuclear weapons formed a balance of terror, ultimately leading to the self-dissolution of the Soviet Union |
| 1990s to Present | United Kingdom, France | Germany | Peace, reunited Germany bound within the European Union and the Eurozone |
As high as a 75% probability that conflicts were resolved through war
How Did Those 4 “Peaceful Exceptions” Achieve It?
Since most transitions ended in war, how did the few peaceful cases successfully avoid the trap?
| Period | Ruling Power (Hegemon) | Rising Power (Challenger) | Key Factor |
|---|---|---|---|
| Late 15th Century | Portugal | Spain | Third-party mediation, the Pope directly drew the line, cutting the New World in half |
| Early 20th Century | Great Britain | United States | Hegemon recognized reality, Great Britain pragmatically chose concession and cooperation, actively sharing power |
| 1940s-1980s | United States | Soviet Union | Balance of terror, both sides had nuclear weapons, Mutually Assured Destruction (M.A.D), whoever shot first died first |
| 1990s to Present | United Kingdom, France | Germany | Alignment of interests, binding Germany to the EU and the Eurozone, defusing conflict through economic integration |
Peace is not built on mutual trust, but on the fact that the cost of action is too high.
The US-Soviet Cold War was one of the most perilous. Although the two sides fought numerous regional proxy wars, because they both possessed nuclear weapons and knew that an all-out war would mean the end of the world, they established a mechanism known as Mutually Assured Destruction (M.A.D. mechanism).
The most dangerous moment was the Cuban Missile Crisis. The Soviet Union deployed nuclear missiles in Cuba, while the United States placed nuclear weapons in Turkey and Italy.
Ultimately, through a political bargain between Kennedy and Khrushchev, the Soviet Union withdrew its nuclear missiles from Cuba, and the United States guaranteed not to invade Cuba, defusing the crisis.
US-China Relations: A Thucydides Trap in Action?
Currently, the most watched dynamic in the world is the structural contradiction between the United States (Hegemon) and China (Challenger).
| Role | Perspective |
|---|---|
| US looking at China | You are trying to challenge the international rules I established and take my position as the tech leader |
| China looking at US | You are uniting with allies to contain me, simply because you do not want to see me strong |
Chinese leader Xi Jinping once publicly cited this term and warned:
“We all need to work together to avoid the Thucydides Trap.”
In 2018, then-US President Trump initiated a trade war against China, imposing tariffs on almost half of the goods exported from China to the United States.
The outside world generally believes that this is a classic response to falling into the Thucydides Trap. The consequences of the trade war are very real:
- Restructuring of global supply chains
- Rising prices
- Accelerated decoupling of the tech industry
This is not a superficial problem that can be solved by changing a president or negotiating a trade agreement; it is a structural contradiction.
Does the Academic World Really Agree with This Theory?
Although the Thucydides Trap theory has had a massive influence, there are also different voices in academia.
American foreign policy scholars Hal Brands and Michael Beckley proposed an opposite viewpoint:
The driver of war is not because the challenger is rising, but because the challenger’s rise has begun to plateau.
They believe that several of Graham Allison’s cases actually conform to another model:
| Model | Logic |
|---|---|
| Thucydides Trap | The challenger continues to grow stronger → the hegemon becomes fearful → War |
| Alternative Theory | After rapid growth, the challenger suddenly plateaus → expects a sharp decline → rushes to seize resources before it’s too late → War |
They gave a few examples:
| Event | Trigger Cause |
|---|---|
| World War I | Germany’s economic growth began to slow down, prompting it to take aggressive action |
| Pacific War | Japan foresaw that its resources would be insufficient to sustain long-term competition |
| Russo-Japanese War | After its peak development, Japan was eager to consolidate its existing gains |
The most dangerous trajectory in world politics is a long-term rise, followed by an expectation of a sharp decline.
This viewpoint has also been used to analyze current US-China relations.
They argue that China’s current slowing economic growth and international resistance, generating anxiety that “the peak has passed”, might be the real driver of conflict.
Only by Understanding the Underlying Logic Can You Make Sense of the News
Whether or not you agree with the Thucydides Trap theory, one thing is certain:
Understanding this framework helps you see through the power structures behind international news.
The next time you see news like “US and China sanction each other again” or “a country’s military exercises have escalated”, try to think using the “hegemon vs challenger” framework:
- Who is the ruling hegemon? Who is the rising challenger?
- Where do the fears and anxieties of both sides originate?
- Is anyone building “guardrails”? Or are both sides accelerating toward a collision?
In an era of volatile international relations
Maintaining the capacity for independent thinking is more important than taking sides.