Will there be war between the US and Iran? Such a question requires, if an answer is to be made, a degree of information, intuition, and near-godlike predictive power that lies beyond the capacities of this (or, I suspect) any other pundit.

But as a student of political philosophy, an analyst of legal scholarship, and a reader of Hugo Grotius – author of The Rights of War and Peace (1625) – I may at least claim the right to say whether there are grounds, reasons and defenses adequate to claim that such a war is justified: It is.

While this essay will sometimes refer to the arguments of Grotius, no claim is made that he is the author of or a discoverer of “international law” (a phrase invented, without much recourse to supporting fact, by Jeremy Bentham). Immanuel Kant, among others, says Grotius is only making a justification for certain kinds of military action, both defensive and offensive, so giving “sorry comfort” to warriors. Kant reminds us that Grotius’ codes have no legal force at all, since states are not subject to a “common external constraint.”

Grotius is discussing war and the right of nations to resort to it in terms that are purely empirical, descriptive, extralegal and pragmatic. He tells us how war is consistent with human nature and natural law, and is an inescapable social reality. The rights (and wrongs) he discovers are a consequence not of international law but of inevitable necessity.

And so, when we discover, as we will during the exposition of this argument, that war between the US and Iran is consistent with natural rights, especially rights possessed by the United States of America, we may rightly fear that a dangerous international disequilibrium may be produced in the absence of countervailing actions by third parties. Therefore, the rest of the world will be wise to make adjustments to prevent the outbreak of such a conflict, because war’s costs will not be confined to the major players.

When we discover, as we will during the exposition of this argument, that war between the US and Iran is consistent with natural rights, especially rights possessed by the United States of America, we may rightly fear that a dangerous international disequilibrium may be produced in the absence of countervailing actions by third parties

Grotius’ “nation” about which he felt sincere patriotism was the United Provinces. That political entity consisted mainly of Holland and Zeeland. It was a kind of republic. It was a kingdom with a vacant throne, kept empty for 50 years after the king of Spain had been driven from it. With feudal Spain gone, the seven but “headless” (United) Provinces were governed by a combination of stadtholders, and representatives of local assemblies who were sent to an Estates General that met at The Hague, where the majority of provinces appointed the Prince of Orange as their common stadtholder.

The resulting conglomeration of monarchical and republican power was made more complex by the appearance (1602) of the Dutch East India Company (Grotius’ family, the De Groots, were shareholders and board members): in addition, influence was wielded by the Calvinist Church, which hoped to control the population via its influence over the Prince, and as well by a group of elites (the De Groots among them) whose power base was in the “civilian” assemblies. Although the stadtholder was commander-in-chief of the military, foreign policy was made by the East India Company, and domestic affairs were fought over by Church and Civilians.

Not surprisingly, a de facto civil war swirled around him during much of Grotius’ life. He played “the Big Game” in earnest, attempting to dethrone the stadtholder in order to end the “tyranny” of the Calvinists, whose intolerance was anathema to him. He lost that fight. His good friend and political ally, a onetime prime minister of the United Provinces named Oldenbarnevelt, was beheaded, and Grotius was imprisoned. He escaped when his wife delivered to him a set of books in a basket: She carried him back out of confinement, concealed in that basket. He then left the country. He spent the last 24 years of his life in part-time exile, supported by diplomatic and political jobs in France, Sweden and Germany.

And so it is no surprise to know that Grotius’ ideas about the practical rules by which he recommended which sort of wars were just and which were unjust were complex and applicable to individuals, to state and non-state actors who operate, according to human nature, out of self-interest, profit, self-preservation, always with an aim to limit costs and protect hard-won property, all in the context of Republicanism and respect for individual rights. There is a notable absence in his analysis of the rights of war or any mention of direction from (far) above, or support for absolutism, as from divine authority. His “morality” is pragmatic.

According to Grotius, three just causes for war are self-defense, a need to repair a past injury or avoid a threatened one, and to punish malefactors.

“First, that It shall be permissible to defend [one’s own] life and to shun that which threatens to prove injurious; secondly, that It shall be permissible to acquire for oneself, and to retain, those things which are useful for life … each individual may … prefer to see acquired for himself rather than for another, that which is important for the conduct of life.”

Perhaps because of his experience with the Dutch East India company, for him, private war was is legitimate. There is a defensible right “of innocent Profit; where I only seek my own Advantage, without damaging any Body else.” An aspect of the right to repair a past or threatened injury, public or private, is the right of a state to punish another state for bad behavior: some rights “of the magistrate comes to him … from private individuals; … the right of chastisement was held by private persons before it was held by the state [and therefore the state may inflict) punishment for wrongs against itself, not only upon its own subjects but also upon foreigners.…“

The rights of war are selfish: “by nature’s ordinance each individual should be desirous of his own good fortune in preference to that of another….”

War against barbarism is just: “War may be justly undertaken against those who are inhuman to their Parents; …  against those who eat human Flesh … and against those who practice Piracy…. The Power of Punishing … proceeds from the Law of Nature.”

According to Grotius a just war cannot be waged using the claim that the “enemy’s” religion is false: “That there is a Deity, … and that this Deity has the Care of human Affairs, are Notions universally received, and … those who first attempt to destroy [any variety of these universal] Notions, ought … to be restrained.…”

In his publication Freedom of the Sea (Mare Liberum, published 1609), Grotius promoted the idea, contrary to the claims then made by the English, that the sea was common international property and thus freedom of movement upon it was essential to trade, and productive of the benefits therefrom. By implication that freedom of use could be defended by private or public just war. Grotius also believed that minor powers should not attempt war against major powers when those great players have the capacity, in general, to do good in the world in ways that benefit third or distant nations.

Grotius’ rules for just war allow the US to say Iran has damaged American public and private property by interfering with maritime freedom of movement, by barbarous conduct within and without its own borders, and by religious intolerance. America may justly claim a right to punish Iran’s general bad conduct, consisting in its attempt to advance its power and influence over all third-party players in the Middle East and because of the threats it regularly makes against American allies in the region. If Iran ever had a cause to wage war against the US, because of damage done, for example to it by American sanctions, its claim is weakened by application of Grotius’ rule that war damage inflicted upon America limits US ability to do good things in the rest of the world. Of course, nonetheless, Iran may claim self-defense when it resorts to actual (albeit furtive) war against American interests in Syria, Iraq and Afghanistan.

And so, the US and Iran, each by their own Grotius-type calculus, have a “right” to wage war. It will be up to third-party nations, especially recalcitrant Europeans, to recognize the potential damage to their own interests, and thus to take sides, making the likely outcome of war so ruinous – to Iran – that the generally desirable and clearly stated American goal – never any atomic weapons for Iran – is realized without need of violent conflict.

Why must Iran lose? Because America cannot – rather will not. That political pragmatic reality, were Grotius the empirical observer still with us to tell us so, is simply a fact about authentic political power.

Author’s note: All quotations are from Grotius Vol I, The Rights of War and Peace (with introduction) edited by Richard Tuck, published by Liberty Fund 2005.