With less than 20.000 words, Kant was able to describe a kind of peace that could – in theory – be everlasting if only – as Mearsheimer, Morgenthau and other Realist Critics of Kant are saying, nations were not as power hungry as they are, defined by competition rather than moral ideals and thus making perpetual peace unattainable. (1)
Nevertheless, Kant’s work divided into Preliminary Articles (to prevent war) and Definitive Articles (to create a lasting peace) laid the foundation for much of the modern thinking on international relations, law and later on updated by Habermas, cosmopolitanism. (6) It remains one of Kant’s most influential political writings, and yet – even though we celebrated his 300s birthday in 2024 – we find ourselves waking up in a world increasingly in turmoil – according to Global Peace Index 2024 (the 12th consecutive time in the last 16 years that the world became less peaceful), (4, 5) contradictory to where Kant saw everything developing into as well as Pinkers famous “long peace”, who argued that we’ve become more peaceful over time. (8)
The Framework
“The problem of organizing a state is solvable even for a nation of devils (if only they have reason)”. (10) If individuals (or rulers) – even if driven by selfish or malicious motives – are sufficiently rational, they will see that the best way to avoid harm and ensure stability is by agreeing to laws and institutions that protect everyone’s rights. The brilliance of a republic or a just constitution according to Kant is, that it “coerces” even bad actors into lawful behavior. It channels self-interest in such a way that any attempt to break the law is riskier than abiding by it. Although moral virtue is paramount here, he acknowledges that not everyone will act from purely moral motives. Therefore, political structures must be robust enough to “force” rulers and citizens to act justly, even if their personal intentions are not virtuous. If that’s the case then any nation can survive any government. (2)
In a similar fashion Acemoglu & Robinson’s argue in their book “why nations fail” – for which they received the nobel-prize in economics in 2024 – how inclusive institutions align self-interest with collective good, showing just how relevant the Königsberger philosopher is even today. (3)
Kant as one of the great satirists of his time took the title for his text from a small tavern near the cemetery which laid on his daily walking route. (9)
With it, he argues that all reasonable rights and politics must strive to realize peace, that’s their only goal to the extent that laws and regulations are there to form an understanding of freedom. Personal freedom which ends at the line of freedom for any other person. In a state we exist next to each other as individuals in our spheres of freedom, simply organized by the government. No reasonable institution will start any wars, he’d say. They were initially founded to maintain peace. Therefore, it would be a contradiction to use its citizens and their life’s as pawns in a game of war. It would go against every moral ideal. But just because it didn’t happen as he predicted, doesn’t mean Kant was wrong, it just goes to show the condition of the world in which unreasonableness is seemingly far reaching. Unreasonableness in the sense of a tendency for escalation and war.
Kant was undeniably optimistic on his worldview stating that reasonable and peaceful governments will continue to thrive on peace. More peaceful states form the free will of the people and convey ever more peace until the world is united under shared laws and mutual agreements. Somewhere along the way this optimism has left us and almost none of that eventually happened thus far. We are rather connected to states that are increasingly governed by autocrats which questions the very idea of Kant. The UN started out with mostly democratic states (with the exception of the soviet union at the time) but now consists of more and more autocratic systems even in relation to the overall increase of countries that joined.
Let’s look into Kant’s text (10)
6 Preliminary Articles
1. “No treaty of peace shall be regarded as valid, if made with the secret reservation of material for a future war.”
Kant argues that peace treaties must not include hidden clauses that could reignite conflict, meaning that diplomatic agreements should be transparent to avoid misunderstandings that could lead to another war down the line. He critiques the idea of temporary peace agreements, such as armistices, as being insufficient in achieving true peace, which he defines as the complete cessation of hostilities. He asserts that any causes for future conflict must be thoroughly eradicated in the process of concluding peace, rather than deferred or hidden for opportunistic exploitation.
Kant condemns the practice of retaining unspoken reservations (mental reservations) or future claims that may reignite conflict once conditions become more favorable. He labels this approach as deceitful and unworthy of statesmen or rulers and as a form of moral reasoning which he regards as manipulative and dishonorable. Furthermore, he critiques the concept of statecraft that prioritizes the continuous expansion of power as the ultimate measure of a state's honor, arguing that such a perspective is overly pragmatic and detached from true moral principles.
Kant's argument emphasizes the necessity of sincerity and a genuine commitment to peace, suggesting that any agreement lacking these qualities undermines the very idea of perpetual peace.
But how realistic is such transparency these days really?
2. “No state having an independent existence—whether it be great or small—shall be acquired by another through inheritance, exchange, purchase or donation.”
Kant rejects the treatment of states as possessions of rulers, challenging feudal and dynastic practices. While this article may seem archaic today, it speaks to the broader principle of respecting national sovereignty. Instead, he discusses the nature of a state as a moral entity and critiques practices that undermine its moral and political integrity. He argues that a state is not a form of property (like land or patrimony) but a collective of individuals who possess self-determination. Consequently, no external entity has the right to command or dispose of a state without its consent. To annex or merge a state with another, thereby subsuming its identity as a moral entity, contradicts the principles of the original social contract, which serves as the foundation for the legitimacy of any governance over a people.
Kant highlights the dangers posed by historical practices such as the acquisition of states through inheritance or marriage alliances which were common in European history. He criticizes these methods as manipulative strategies for consolidating power or expanding territories without the consent of the populations involved. Such practices, Kant suggests, reduce states and their citizens to mere objects or commodities, stripping them of their moral agency.
Additionally, Kant critiques the hiring out of troops from one state to another for conflicts unrelated to the hiring state. This practice, he argues, treats the citizens as expendable resources rather than as autonomous individuals, further violating the moral principles that should govern the relationship between a state and its people. Overall, Kant emphasizes the need for respecting the moral personhood of states and their citizens in the pursuit of just and lasting peace.
3. “Standing armies shall be abolished in course of time.”
Kant believes maintaining large, permanent armies only provokes suspicion and arms races. He endorses a gradual path to disarmament – still a contentious topic in contemporary international relations. He critiques the perpetual preparation for war and the accumulation of military resources by states. Kant argues that the readiness for war, demonstrated through the constant build-up of armed forces, creates a cycle of insecurity and provocation among nations.
This competitive arms race leads to immense financial burdens, making the costs of maintaining peace even more oppressive than those of a short war. Such conditions often push states toward preemptive or aggressive wars as a way to escape the economic strain of military preparedness. Kant also condemns the practice of hiring soldiers to kill or be killed, likening it to using humans as mere tools or machines controlled by the state. This, he asserts, violates the inherent dignity and rights of humanity, as it disregards the moral worth of individuals. In contrast though, Kant supports the idea of voluntary and periodic military training for citizens to defend their homeland. Such practices, he argues, align better with the principles of justice and human rights, as they do not exploit individuals for state-driven objectives but rather empower them to protect their own nation.
Kant further critiques the hoarding of wealth (as a "treasury") for potential war efforts, which, like the build-up of military forces, is seen as a threat by other nations. This perception can lead to preemptive attacks, as financial power is regarded as one of the most reliable tools of warfare. Thus, Kant underscores how both military and economic preparations for war undermine the possibility of lasting peace.
4. “No national debts shall be contracted in connection with the external affairs of the state.”
Kant warns against the accumulation of public debt to finance wars. This resonates with contemporary debates on military spending and economic policy. More specifically he addresses the economic mechanisms that states use to sustain their activities, particularly focusing on the credit system.
Kant begins by distinguishing between legitimate uses of external or internal financial support, such as improving infrastructure, establishing settlements, or preparing for potential crises like crop failures, which he deems unproblematic. However, he critiques the use of credit as a means to amass resources for military purposes. Kant describes the credit system, an innovation of the mercantile nations of his time, as a "dangerous financial power."
This system enables states to accumulate seemingly unlimited debt under the assumption that not all creditors will demand repayment simultaneously. It effectively creates a vast financial reservoir for war efforts, surpassing the combined wealth of other nations. This capability, paired with the rulers' innate propensity for war, fosters a dangerous ease in waging conflicts, undermining efforts toward perpetual peace. Kant warns that the inevitable collapse of such a credit system – when debts can no longer be sustained – would not only bankrupt the state itself but also drag other, uninvolved nations into economic turmoil. This would constitute a public violation of justice against these states.
Therefore, Kant argues that prohibiting the use of credit systems for war financing should be a preliminary article in the pursuit of perpetual peace. He further suggests that other nations are justified in forming alliances to oppose states that exploit such systems for aggressive purposes. This critique underscores Kant's emphasis on economic justice and the dangers of tying national finances to militaristic ambitions.
5. “No state shall violently interfere with the constitution and administration of another.”
Kant advocates the respect of each state’s political autonomy, foreshadowing principles in the UN Charter regarding non-interference. He discusses the illegitimacy of external interference in the internal affairs of a sovereign state, thereby asking what could justify such interference, particularly in cases where the behavior of a state might be seen as scandalous or troubling to others. He argues that a state's internal problems, even if they stem from lawlessness, can serve as a cautionary example to other nations rather than a legitimate reason for intervention.
The negative example set by a free state should not be seen as a violation of others’ rights. Kant makes an exception for cases of internal division, where a state has split into two factions, each claiming to represent the whole. In such situations, assisting one faction might not count as interference in the internal constitution of the state, as the situation represents anarchy rather than a unified state. However, until such a division is resolved internally, any intervention by external powers constitutes a violation of the rights of a sovereign people struggling with internal challenges. He emphasizes that such interference would undermine the autonomy of all states, making their sovereignty precarious.
External involvement in unresolved internal disputes sets a harmful precedent and destabilizes the principles of self-governance and non-interference that are essential for perpetual peace. This critique reflects Kant's broader insistence on respecting the independence and autonomy of nations, even in the face of internal disorder.
6. “No state at war with another shall countenance such modes of hostility as would make mutual confidence impossible in a subsequent state of peace: such are the employment of assassins or of poisoners, breaches of capitulation, the instigating and making use of treachery in the hostile state.”
Kant suggests moderation during war times to preserve the possibility of peace. Modern notions of war crimes and international humanitarian law reflect a similar spirit. He thereby condemns dishonorable war tactics that erode the trust necessary even between enemies during conflict. Kant argues that some level of mutual trust regarding the opponent's disposition must remain intact during war, as it forms the basis for negotiating peace. Without this trust, hostilities could escalate into wars of extermination, which Kant sees as an extreme and unacceptable outcome.
War, in Kant’s view, is a regrettable necessity in the absence of a judicial authority capable of resolving disputes. It serves as a means for states to assert their rights through force, but neither side can claim to be definitively just, as such a determination requires a higher adjudicator. Punitive wars, which presume a superior-subordinate relationship between states, are therefore conceptually untenable.
Kant warns that wars of extermination would lead to the ultimate destruction of both parties, along with all legal principles, leaving "eternal peace" to exist only in the metaphorical graveyard of humanity. Consequently, such wars and the tactics that enable them are categorically impermissible.
He further criticizes strategies such as deceit, treachery, or other "hellish arts" that corrupt the moral fabric of war. These methods, Kant argues, not only degrade warfare itself but also risk extending their destructive influence into times of peace. Practices like espionage, while exploiting the dishonesty of others, illustrate how dishonorable conduct can persist beyond war, undermining the very foundations of peace. For Kant, these tactics contradict the moral objectives of justice and peace and must therefore be strictly prohibited.
3 Definitive Articles
1. “The civil constitution of each state shall be republican.”
By “republican,” Kant primarily means a constitution with separation of powers, representation, and the rule of law. Republican states, Kant reasons, are less likely to wage wars because citizens themselves bear the costs of war (in blood and taxes), making them more cautious about conflict. He argues that the only constitution capable of ensuring a just political order and leading toward lasting peace is a “republican” one. He defines this constitution through three core principles: (1) the freedom of each individual as a human being, (2) the subjection of all to a single common legislation as subjects, and (3) the equality of everyone as citizens.
Kant claims that a truly republican system requires that the legislative and executive powers be kept separate. When citizens themselves must decide whether to go to war – recognizing that they will bear its burdens – they will be far more cautious in making such a decision. In contrast, a government where a ruler can unilaterally launch a war (without having to endure its costs) more easily drifts into conflict.
Kant also clarifies that “republican” should not be confused with “democratic” in the sense of direct rule by the people. In fact, Kant labels pure democracy as a kind of despotism if the same body that makes the laws also enforces them.
For Kant, any non-representative system, no matter how formally structured it is (monarchy, aristocracy, or democracy), risks devolving into despotism. The key to a genuine republic is a representative form of government in which the people’s will is reflected by those entrusted with legislative power, while the executive branch operates independently according to those laws.
2. “The law of nations shall be founded on a federation of free states.”
Kant envisions a voluntary league or federation of sovereign states united not by an over-arching global government, but by shared laws and mutual agreements to protect each other’s independence and peace. He sets out this article, arguing that international law should be based on a federation (rather than a single global state) of free, independent nations. States, like individuals in a lawless “state of nature,” cannot reliably ensure their rights or security on their own. Although each state resists external constraints on its “majesty,” Kant insists that they must voluntarily form a federated union, that can guarantee peace without merging all states into one single sovereignty.
He stresses that simple peace treaties, which only end a single conflict, are insufficient. A lasting peace requires a stable framework that prevents wars from arising in the first place.
Kant believes that, even if a global “world republic” is impossible in practice, the federation model can gradually expand as more states realize that cooperation benefits everyone. Despite humanity’s persistent inclination toward conflict, Kant sees hope in the fact that even warring nations still invoke the concept of “right,” indicating a latent moral capacity to overcome war through law and mutual agreement.
3. “The rights of men, as citizens of the world, shall be limited to the conditions of universal hospitality.”
Kant introduces the idea of “universal hospitality,” allowing visitors to enter foreign lands without facing hostility, so long as they respect local laws. While not equating to unrestricted immigration, it establishes moral obligations to treat foreigners as potential fellow citizens of a global community. Kant introduces here the idea of “cosmopolitan right,” limiting it to conditions of universal hospitality. This doesn’t mean charity or kindness, but a fundamental right ensuring that a foreign visitor, arriving peacefully on another’s territory, must not be treated with hostility. While the host may refuse entry if it does not threaten the visitor’s survival, the visitor has at least a right to attempt peaceful interaction.
Kant argues that humanity shares the Earth’s surface and cannot spread out infinitely, so people must learn to coexist. He critiques European colonial powers for their brutal conduct – equating “visiting” with conquest – and notes that some nations, such as China and Japan, severely restrict foreign entry in response to past aggressions. Because wrongs in one part of the world are increasingly felt everywhere, Kant sees cosmopolitan right as the necessary next step in international law, guiding humanity toward a truly global civil society and, ultimately, perpetual peace.
Wars are highly inefficient
A perpetual peace must be based on a rule-based governing structure of countries both on the inside and in relationship to each other. This is hard to come by with autocratic forms of government. But why do wars even start? They cost a lot, destroy more than they do good – always. If wars are irrational, then the approaches of Kant, Habermas, and others – who place the rational, reason-endowed, and proactive human being at the center – prove to be valid only to a limited degree. There seems to be an innate human tendency toward destruction, ultimately a death drive, which manifests in minor acts such as vandalism and everyday hatred and finally culminates in acts of war. But humiliating and tormenting others are mainly projections of self-hatred. When a fulfilling life is made impossible, destructive impulses break through. This coincides with the tendency toward “evil” that Kant attributes to humanity. However, where matters of law and state are concerned, such impulses must not play any role. War and peace must not be determined by personal, individual mindsets – otherwise, we would end up with a system of justice driven solely by ideology. (11)
Make peace with yourself, then with your enemy, and eventually among states. The law represents external peace – coordinated by us under legal frameworks – allowing individuals and states to grow side by side in harmonious comparison.
John Rawls, in his Theory of Justice, argues that all values in a state can be negotiated except for human dignity. He explicitly refers to Kant here: behind the veil of what any subject wants or doesn’t want, dignity must always be upheld. Despite everything, establishing peace must ultimately remain the highest political goal. (12)
The peace of Westphalia – just like many other diplomatic peace negotiations at that time – which was concluded 1648 after 5 years of continuous negotiations started out with a huge banquet and an opulent meal. Maybe it’s time we go back to basics and start there with peace at the table.
by mario
Bibliography:
- Mearsheimer, John J. – The Tragedy of Great Power Politics. New York: W.W. Norton, 2001.
- Kant – „Über den Gemeinspruch: Das mag in der Theorie richtig sein, taugt aber nicht für die Praxis“ (1793).
- Acemoglu, D., & Robinson, J. A. (2012). Why nations fail: the origins of power, prosperity and poverty. New York, Crown Publishers.
- https://www.economicsandpeace.org/wp-content/uploads/2024/06/GPI-2024-web.pdf (last visit: 30.12.2024)
- https://ucdp.uu.se/ (last visit: 30.12.2024)
- Habermas, Jürgen – The Postnational Constellation, trans. Max Pensky, Polity Press, 2001, p. 107)
- https://www.democracywithoutborders.org/31834/freedom-in-the-world-report-2023-was-18th-consecutive-year-of-decline/?utm_source=chatgpt.com (last visit: 30.12.2024)
- Pinker, Steven. The Better Angels of Our Nature: Why Violence Has Declined. Viking, 2011
- https://oxnzeam.de/wp-content/uploads/2015/11/kant-zum_ewigen_frieden.pdf (last visit: 31.12.2024)
- https://www.gutenberg.org/files/50922/50922-h/50922-h.htm (last visit: 31.12.2024)
- Schäfer, Reinhard – Der ewige Frieden. https://www1.wdr.de/mediathek/audio/wdr5/wdr5-das-philosophische-radio/index.html (last visit: 30.12.2024)
- Rawls, John. A Theory of Justice. Harvard University Press, 1971
Background Info:
Boehm & Kehlmann – Der bestirnte Himmel über mir. Ein Gespräch über Kant. 2024
