Pacifism and game theory
Can Peace Be a Winning Strategy? A Game Theory Thought Experiment
So, I was going through game theory a while back and was curious to see it interact with a philosophy I was extremely interested in at the time. Pacifism.
Basically I wanted to look at four themes-
1. Is pacifism possible?
2. If yes, what are the factors that must be fulfilled in order for the possibility of pacifism to become a reality?
3. Is Pacifism sustainable?
4. Is it desirable?
Let’s start with a few obligatory definitions. Pacifism, as defined (loosely) by Wikipedia and others, is the opposition to war and violence. That’s the core idea - simple, but deceptively deep.
There are three primary levels at which pacifism can operate:
International - Between nation-states. Pacifism here means countries refrain from developing arms, avoid military buildups, and refuse to engage in wars or threats of war.
National - Between the state and its citizens. This includes things like demilitarised policing, non-lethal crowd control, or legal nonviolence.
Personal - Between individuals. Think Gandhi, civil disobedience, or nonviolent protest.
This post focuses exclusively on international pacifism — whether and how it can exist between countries. I've written this post about why national-level pacifism may be pragmatically sound; but this one tackles the global lens.
Let’s assume two countries : Country A and Country B - of roughly equal size and power. Each has two options:
Arm: Invest in weapons, troops, and defenses (at a cost of 10 units).
Disarm: Avoid all military preparation and refuse to stockpile weapons.
The costs to either country can be depicted in the following table:
Now, here’s the interesting part: if we only consider direct costs, both countries would prefer not to arm. Disarming avoids the 10-unit cost: so from a narrow economic lens, disarmament is the dominant strategy for both.
But realpolitik isn’t so simple.
Let’s add another layer: what happens if war breaks out?
If both countries arm and war occurs, each suffers an additional loss of 790 units (on top of the 10-unit upkeep).
If only one country arms, the disarmed country faces a catastrophic loss of 1500 units.
If neither arms, there’s no physical war - but almost certainly, there will be cold war dynamics or economic sanctions.
And here’s where the ambiguity creeps in: the cost of sanctions is variable. It’s real - but unpredictable. This gives rise to two strategic scenarios we’ll now explore.
A) When the sanction war costs more than what the upkeep of weapons cost: Let's say the sanction was costs 50 currency units to both countries. Note that all these numbers are purely theoretical - and the quantum doesn’t matter here as much as the relative cost.
From the matrix:
If Country A disarms, and Country B arms, A suffers a catastrophic loss of 1500, while B only loses 10.
If both arm, they each lose 800. This includes the cost of maintaining arms and war losses.
If both disarm, they suffer 50 due to sanctions and cold war–like tensions.
What’s the best strategy for a country, regardless of what the other does?
If B chooses Weapons, A is better off choosing Weapons (loss of 800 vs 1500).
If B chooses No Weapons, A is still better off choosing Weapons (loss of 10 vs 50).
This means Weapons is a dominant strategy for both. No matter what the other country does, arming yields a better outcome. Hence, both countries logically choose to arm - not because it’s ideal, but because it’s the safest self-interested move.
This leads to a classic Nash Equilibrium: neither side has an incentive to unilaterally deviate. Both arming is stable, even if mutually worse than cooperation.
B) When the sanction war cost is less than what the upkeep of weapons cost. Let's say 5 currency units.
As can be seen - this game has two Nash Equilibria:
Mutual Armament (–800, –800)
Mutual Pacifism (–5, –5) - but only stable under mutual trust
So pacifism is possible here - but it's a coordination problem, not just a cost problem.
So now this gets interesting. To ensure that the countries adhere to pacifism, we need to make sure that:
So, what would it take for countries to truly commit to pacifism?
1. Minimize Dependence or Diversify Risk
A country must not rely excessively on any single trade partner. Either:
Its trade must be diversified, or
It must be largely self-sufficient.
This reduces the threat of economic sanctions - which in turn makes disarmament safer. When the cost of sanctions exceeds the cost of weapons, no rational state will give up its arms.
2. Pacifism Requires Universal Coordination
No state will disarm unilaterally. The only condition under which a country will choose pacifism is if every other country credibly commits to it too. Even if weapons are costlier than peace, the risk of being the only disarmed nation in a militarised world is too great.
This is the classic Nash trap: individual rationality leads to a collectively worse outcome.
3. The Temptation of Dominance Breaks the System
If all countries were to disarm, the incentive to defect becomes massive.
The strategic and political gains from acquiring weapons in a pacifist world : dominance, deterrence, imperial leverage : are immeasurable.
These "benefits of breaking the pact" don’t appear in our cost matrix because they’re hard to quantify. But they’re real : and they destabilise pacifism from within.
So to answer the question posed in the beginning of the article-
1. Is pacifism possible?
On an international level, it seems unlikely - at least if we're assessing it through the lens of strategic self-interest. If countries are trying to maximize long-term outcomes like security, leverage, and global influence, pacifism loses out. The payoff for retaining weapons - especially when others disarm - is simply too high.
That said, if nations act not out of self-interest but out of principle, the answer changes. Pacifism then becomes a moral stance, not a strategic one. And perhaps, just perhaps, morality has utility after all.
2. If yes, what are the factors that must be fulfilled in order for the possibility of pacifism to become a reality?
For pacifism to be a viable equilibrium, two conditions must be met:
Universal commitment: Every country must adopt the stance simultaneously.
Credible enforcement: There must be ironclad contracts or third-party institutions with real consequences for defection.
Absent these, the incentives to cheat - or to arm defensively - will always creep back in.
3. Is Pacifism sustainable?
It depends on the foundation it's built on.
If pacifism is pragmatic (i.e., chosen because it seems cheaper or easier short-term), then no - it's fragile.
If it’s principled, based on shared values or ethical commitments, it might last longer - but it’s hard to scale that across borders and ideologies.
4. Is it desirable?
Absolutely, in my view, yes. Not just because it's peaceful, but because it's an aspiration that forces us to confront what kind of future we want to negotiate toward.