Guardians Of The Strait: What Pope Leo XIV Asks Of Us When The Sea Becomes A Weapon

The war between the United States and Iran is back, and the fighting has moved onto the water that carries a fifth of the world’s energy. On July 14 the U.S. reinstated its naval blockade of Iranian ports, tankers are burning across the Strait of Hormuz, a seafarer is dead, and the presidents of both countries have taken to calling themselves the “guardian” of the strait. When the sea itself becomes a weapon, a Catholic has to ask the older question underneath the headlines: what does the Church actually teach here, and what does she ask of you and me? This year that question has a fresh and pointed answer, because Pope Leo XIV has just spoken to it directly.

The News Story

The United States reinstated a naval blockade of Iran’s ports on July 14, sharply escalating a renewed war over the Strait of Hormuz after an interim ceasefire collapsed. U.S. Central Command announced the blockade would take effect at 4 p.m. Eastern time, resuming an operation that had run from April 13 to June 18 before being lifted a day after a June 17 memorandum of understanding paused the fighting. The 14-point accord set a 60-day window to negotiate a final deal and settle control of the strait, but both Washington and Tehran now say they no longer consider the memorandum binding. [1]

The blockade announcement followed days of intensifying strikes. On Monday night, the U.S. military said it hit Iranian air defenses, missile and drone sites, and “maritime capabilities” in the port cities of Bushehr and Bandar Abbas to “degrade Iran’s ability to attack commercial shipping.” On Tuesday, further U.S. strikes hit the Khuzestan cities of Abadan, home to the Middle East’s oldest oil refinery, and Mahshahr, along with Qeshm Island, according to Iranian state media. A U.S. official told Reuters that additional strikes targeted “emerging threats.” [2]

Iran retaliated across the Gulf. The Islamic Revolutionary Guard Corps said it disabled two “non-compliant” supertankers in the strait after they ignored warnings. The United Arab Emirates said two of its tankers were struck by Iranian cruise missiles in Omani waters, killing one crew member; the International Maritime Agency reported two seafarers killed and warned that “the cycle of escalation must end.” Iran also launched missiles and drones at U.S. facilities in Bahrain, which hosts the Navy’s Fifth Fleet, and at outposts in Jordan. Jordan said it intercepted four missiles, Bahrain reported fending off an aerial attack, and Kuwait said its forces engaged “hostile” targets. [3]

President Trump, who declared the ceasefire “over” at a NATO summit in Turkey and formally notified Congress of renewed strikes, said Iran “shot first.” He announced the U.S. would act as “the guardian of the Hormuz Strait,” initially proposing a 20% toll on cargo transiting the waterway, then reversing course and saying he would replace the fee with trade and investment deals with Gulf allies. [4] Iranian Foreign Minister Abbas Araghchi countered that Iran “has always been the guardian of the strait and will remain so forever,” calling 20% “too much.” Deputy Foreign Minister Kazem Gharibabadi accused the U.S. of destroying the memorandum and said Iran no longer holds any obligations under it. [5]

Roughly 20% of the world’s energy supplies pass through the Strait of Hormuz. The data firm Kpler said crossings fell to 22 ships last week, an almost 85% drop from prewar levels. The current war began February 28; Iranian Supreme Leader Ayatollah Ali Khamenei was killed in U.S.-Israeli strikes at its outset and was buried July 9. Mediators Oman, Qatar, and Pakistan continued pressing for de-escalation, though the status of talks remained unclear. [6]

An oil tanker at sea, the kind of commercial vessel now caught in the crossfire in the Strait of Hormuz. Licensed via Adobe Stock, ID 298891924.

Catholic Social Teaching Analysis

Begin with the water itself, because everything else in this story flows from what that water is. The Strait of Hormuz is a narrow neck of sea between Iran and Oman, and a fifth of the world’s oil and gas rides through it every day. That fact can sound like an abstraction until you follow the cargo to where it lands: the diesel in a farmer’s tractor outside Omaha, the cooking fuel in a kitchen in Karachi, the electricity keeping a ventilator running in a hospital in Manila. When two governments start treating that waterway as a chokepoint to squeeze each other, they close their hands around the throat of people who have no part in the quarrel and never agreed to be bargained with. The Church has thought carefully about goods of exactly this kind. The sea, and the routes by which the human family feeds and warms itself, are held in trust for the common good, and no government is permitted to seize them as a private prize.

That’s why the word both men keep reaching for should trouble us. Mr. Trump calls the United States “the guardian of the Hormuz Strait.” Mr. Araghchi insists Iran “has always been the guardian of the strait and will remain so forever.” A guardian, though, protects a thing for the sake of those who depend on it, and a guardian does not stop 85% of the traffic and then charge a toll for the privilege of passage. The word is being used to dress control up as service, and the Church, who has spent 2,000 years watching power borrow the language of protection, teaches us to look straight past the word to the deed. Guardian of what, we should keep asking, and for whom?

Peace Is A Bigger Thing Than A Ceasefire

Before we weigh anyone’s conduct, we should be clear about what we’re even asking for, because the word peace gets used carelessly. The Catechism will not let us settle for the thin version. “Peace is not merely the absence of war,” it teaches, “and it is not limited to maintaining a balance of powers between adversaries.” Real peace is “the tranquillity of order,” and it “is the work of justice and the effect of charity.” [7] The Compendium of the Social Doctrine says the same thing from another angle, teaching that peace “requires the establishment of an order based on justice and charity,” and that “peace is the fruit of justice.” [8] Peace, in other words, is a positive achievement, the settled right ordering of things, and never simply the quiet that falls when the shooting pauses.

Hold that standard against the last month, and the June memorandum looks like exactly what the Church warns against. It was a balance of powers, a 60-day truce held together by mutual threat and some deliberately vague language about “best efforts” to keep the strait open, and it lasted about four weeks before it came apart. That is the natural lifespan of a peace built on fear rather than justice. It buys a little time and then breaks, because the disorder underneath it was never actually healed. None of this means the Church is naive about statecraft. She knows nations sometimes have to sign imperfect agreements to stop the bleeding. Her insistence is only that a truce is the beginning of the real work and never the end of it, and the real work is justice.

Pope Leo XIV Has Closed The Door On Just War Theory

Here is where a reader expects me, a Deacon who loves Saint Thomas Aquinas, to reach for the classical just war theory and start ticking off its conditions. For most of my life, that is exactly what a Catholic writer would have done. Augustine sketched the framework, Aquinas systematized it in the Summa, and for eight centuries the Church reasoned about war through its familiar tests of legitimate authority, just cause, right intention, last resort, proportionality, and the protection of non-combatants. I still think those categories teach us something. But honesty requires me to tell you plainly that the Church has moved, and that the most recent word of her Magisterium now governs.

That word came in May, when Pope Leo XIV issued his first encyclical, Magnifica Humanitas. In paragraph 192, the Holy Father wrote, “Today, more than ever, without prejudice to the right to self-defense in the strictest sense, it is important to reaffirm that the ‘just war’ theory, which has all too often been used to justify any kind of war, is now outdated.” [9] Read that sentence slowly, because it is a genuine development of doctrine and it deserves to be named as one rather than smoothed over. Leo is building on Pope Francis, who had already written in Fratelli Tutti that “it is very difficult nowadays to invoke the rational criteria elaborated in earlier centuries to speak of the possibility of a ‘just war.’” [10] Leo takes that hesitation and states the conclusion outright. In an age of nuclear arsenals and autonomous weapons, the old framework has too often served as a permission slip for the powerful, and the Pope has judged it no longer fit for the Church’s moral analysis of war.

Notice what Leo does not do. He does not make Catholics pacifists, and he does not deny “the right to self-defense in the strictest sense.” What he denies is the machinery by which nearly every war gets baptized as just after the fact. His deeper worry runs through the whole encyclical. He warns of “a troubling revival of war as an instrument of international politics, while the very ethical principles that had previously limited its use are being eroded.” [11] That is a precise description of what we are watching in the Gulf. A ceasefire declared “over” from a podium, an open-ended campaign against “emerging threats,” a waterway turned into a tollbooth, and a President who says the quiet part aloud: “They shot first, and that was a big mistake, because we have been knocking the hell out of them.” That is war revived as an instrument of politics, exactly the normalization Leo names.

Even Aquinas, for all that his framework has now been set aside, would not be scandalized by where Leo has landed, because Aquinas himself insisted that the only lawful purpose of any war is peace. “We go to war,” he wrote, quoting Augustine, “that we may have peace.” [12] Leo XIV pushes that ancient logic to its honest conclusion for our century and asks why, when peace is the only permitted goal, we keep reaching first for the sword. His answer points somewhere else entirely. “Humanity possesses far more effective and capable tools for promoting human life and resolving conflicts,” he writes, “such as dialogue, diplomacy and forgiveness.” [13] That is the operative teaching of the Church today, and it is the standard against which this war has to be measured.

The Sailor In The Water And The Cities Under Fire

Leo does not leave the protection of the innocent to inference. Writing about the new weapons that now decide who lives and dies, he lays down a criterion that lands squarely on this war: “Target selection and the use of force must not confuse combatants and non-combatants, nor ignore the impact on defenseless populations.” [14] Hold that beside the facts. A tanker crew is made of non-combatants, ordinary sailors hauling cargo for wages, and firing on “non-compliant” ships to enforce a claim over the waterway treats those civilians as instruments in a sovereignty dispute. The same criterion cuts hard against the American strikes. Abadan is not an empty missile range; it is a city, home to the oldest refinery in the Middle East and to the families who work it, and Bandar Abbas is a crowded working port.

The older teaching said as much and still stands where Leo has not overturned it. The Catechism reminds us that the moral law does not take leave for the duration of a war, since “the mere fact that war has regrettably broken out does not mean that everything becomes licit between the warring parties.” [15] A strike on a genuine military target can be defensible. A campaign that treats a populated port city as a board to be swept clear cannot, because the line between the fighter and the civilian is the hinge on which the entire tradition turns, and Leo has only drawn that line more sharply for an age that keeps finding new ways to blur it.

A Blockade Is An Embargo, And Rome Saw This Coming

Here the Church’s teaching gets uncomfortably specific, in a way that ought to stop any Catholic cheering the blockade. A naval blockade of a country’s ports is an economic weapon whose whole purpose is to strangle the flow of goods until a government changes its behavior, and the Compendium of the Social Doctrine addresses this exact instrument in language that reads as though it were drafted for July 2026. Sanctions, it grants, aim “to correct the behavior of the government of a country” that breaks the rules of international life, which is fair enough as far as it goes. Then comes the guardrail, and it is unsparing: “Sanctions must never be used as a means for the direct punishment of an entire population: it is not licit that entire populations, and above all their most vulnerable members, be made to suffer.” On the specific tool now in the headlines, the text could hardly be more direct, insisting that “an economic embargo must be of limited duration and cannot be justified when the resulting effects are indiscriminate.” [16]

Sit with what that means on the ground. A blockade that seals Iran’s ports lands on the grandmother who needs imported medicine and the day laborer in Bandar Abbas long before it inconveniences any ayatollah or general, and because this particular chokepoint carries a fifth of the world’s energy, its indiscriminate effects refuse to stay inside Iran’s coastline. They travel down every supply chain until they reach a family in Lagos or Dhaka paying more to eat and to stay warm this winter because fuel turned scarce and dear. This is precisely where Pope Leo’s Dilexi Te, his exhortation on love for the poor, presses on the conscience. “On the wounded faces of the poor,” Leo writes, “we see the suffering of the innocent and, therefore, the suffering of Christ Himself.” [17] The poor of Iran and the poor of the wider world did not start this war and cannot end it, yet a blockade lashed to an open-ended conflict makes them carry it. The Church’s two tests are duration and discrimination, and this one fails both. Reverse the flags, and the judgment would not change by a syllable.

The Sailor Is Not A Thing

This is the point where Pope Leo XIII walks into the room alongside his namesake, and where a Deacon of the Church cannot keep silent. Look once more at what that dead man was doing when the missile found him. Moving cargo across open water is honest and grinding labor, and the men who do it spend months away from their families so that the rest of us can flip a switch and never think about the sea at all. Rerum Novarum, the encyclical that opened the modern social teaching of the Church in 1891, drew a hard line under work exactly like his. Leo XIII condemned any arrangement that would “misuse men as though they were things in the pursuit of gain, or to value them solely for their physical powers,” and he called such treatment “truly shameful and inhuman.” [18] A “non-compliant” tanker, in the cold grammar of this war, is precisely a man reduced to a thing: an object to be disabled, a signal fired at a rival capital and written in another man’s death.

Leo XIII pressed the point even harder, warning that “to defraud any one of wages that are his due is a great crime which cries to the avenging anger of Heaven.” [19] The sailor who dies hauling the world’s fuel through a war zone has been robbed of far more than a paycheck; he has been robbed of the whole life that paycheck was meant to sustain, and the Church counts that theft, and counts it against everyone who decided the water was worth more than the men crossing it. Notice, too, how quickly the vocabulary of commerce crept into a matter of life and death, the 20% toll, the trade deals floated to replace the toll, the “reimbursement” language for providing safety. The strait is being priced like freight. The Catechism reminds us that even the machinery of security answers to a higher law, teaching that “the production and the sale of arms affect the common good of nations and of the international community.” [20] When safe passage on an international waterway becomes a revenue stream, the common good has been quietly demoted beneath the ledger, and a shared inheritance of the family of nations has been repackaged as a private asset with a gatekeeper at the door.

Root Causes And The Longing For A Real Peace

It’s worth asking why any of this happens, because the Catechism refuses to let us pretend wars simply fall out of the sky. “Injustice, excessive economic or social inequalities, envy, distrust, and pride raging among men and nations constantly threaten peace and cause wars.” [21] Every one of those forces is loose in the Gulf right now, and pride is doing the heaviest lifting of all, two men each insisting he is the strait’s one true guardian and neither willing to be seen stepping back first. Pope Leo names the economic root without flinching in Dilexi Te, where he states plainly that inequality “is the root of social ills.” [22] A world ordered so that a fifth of its energy can be held hostage is a world already tilted toward the strong, and the war over Hormuz is partly a fight among the powerful over who gets to work the valve.

The honest way out is the one Leo keeps pointing toward, back to dialogue and diplomacy and the slow labor of disarmament he has favored since the first hour of his pontificate, when he stepped onto the balcony and asked for a peace that is “unarmed and disarming.” The mediators in this story, Oman, Qatar, and Pakistan, are a small and real sign of that path, and when they press both sides back toward the table, they are doing the patient, unglamorous work the Church has always blessed. The road to peace runs through their conference rooms in Muscat and Doha, and it runs there long before it runs through the next salvo.

What This Asks Of You

So what is left for us to do, sitting an ocean away from the Gulf with no fleet to command and no treaty to sign? The Catechism opens its whole treatment of war by pointing us toward two things at once, urging “everyone to prayer and to action so that the divine Goodness may free us from the ancient bondage of war.” Prayer and action, held together, neither one excusing us from the other. So pray, and mean it, for the sailors still out on those ships, for restraint in Washington and Tehran, and for the mediators wearing out their phones. Pope Francis reminds us in Fratelli Tutti that “the first victim of every war is ‘the human family’s innate vocation to fraternity,’” [23] and that vocation is the thing most worth guarding, far more than any waterway. The sailor killed in Omani waters this week was your brother in the only sense that finally matters.

Then act, because prayer that never reaches the hands is only half-offered. Refuse the easy tribalism that cheers our side’s strikes and shrugs off the other side’s dead, since the Church recognizes no such discount on human life. Support the relief agencies, Catholic Relief Services among them, who will be tending the human wreckage of an energy shock long after the cameras have moved to the next crisis. And take Pope Leo XIV’s development of doctrine seriously instead of arguing around it: when a leader tells you a war fought in your name is just, remember that the Church has now judged that very framework outdated, and ask him instead what he has done to try dialogue, diplomacy, and forgiveness first. The bondage of war is ancient, as the Catechism says, and it is heavy, but it has never once been eternal. The strait can become a road again, a place where the goods of the earth move freely to the people who need them, and that is worth both our prayer and our labor this week.

Footnotes

1. “The U.S. Is Set to Reinstate a Blockade over the Strait of Hormuz,” NPR, July 14, 2026, https://www.npr.org/2026/07/14/nx-s1–5893257/us-iran-updates.
2. “US Strikes New Targets in Iran as Tehran Hits Gulf States, Hormuz Shipping,” Al Jazeera, July 14, 2026, https://www.aljazeera.com/news/2026/7/14/us-strikes-new-targets-in-iran-as-tehran-hits-gulf-states-hormuz.
3. “US Naval Blockade of Iranian Ports Goes into Effect,” CNN, July 14, 2026, https://www.cnn.com/2026/07/14/world/live-news/iran-war-trump.
4. “U.S. Blockades Iranian Ports, Launches Strikes as Trump Seeks Control of Strait of Hormuz,” CBS News, July 14, 2026, https://www.cbsnews.com/live-updates/us-iran-war-trump-ceasefire-attacks-strait-of-hormuz/.
5. “US Restores Blockade on Iran after Its Attacks on Ships in the Strait of Hormuz,” The Washington Post, July 14, 2026, https://www.washingtonpost.com/business/2026/07/14/iran-us-hormuz-strait-war-july–14–2026/b82cf3f0–7f3c–11f1–8a16–393bd03340b0_story.html.
6. “US Military Reimposes Naval Blockade on Iranian Ports, Launches New Strikes,” France 24, July 14, 2026, https://www.france24.com/en/middle-east/20260714-us-military-reimposes-naval-blockade-on-iranian-ports-launches-new-strikes.
7. Catechism of the Catholic Church, 2nd ed. (Vatican City: Libreria Editrice Vaticana, 1997), no. 2304.
8. Pontifical Council for Justice and Peace, Compendium of the Social Doctrine of the Church (Vatican City: Libreria Editrice Vaticana, 2004), no. 494.
9. Pope Leo XIV, Magnifica Humanitas (Vatican City: Libreria Editrice Vaticana, 2026), no. 192, https://www.vatican.va/content/leo-xiv/en/encyclicals/documents/20260515-magnifica-humanitas.html.
10. Pope Francis, Fratelli Tutti: On Fraternity and Social Friendship (Vatican City: Libreria Editrice Vaticana, 2020), no. 258, https://www.vatican.va/content/francesco/en/encyclicals/documents/papa-francesco_20201003_enciclica-fratelli-tutti.html.
11. Pope Leo XIV, Magnifica Humanitas (Vatican City: Libreria Editrice Vaticana, 2026), no. 190, https://www.vatican.va/content/leo-xiv/en/encyclicals/documents/20260515-magnifica-humanitas.html.
12. Thomas Aquinas, Summa Theologiae, II-II, q. 40, a. 1, trans. Fathers of the English Dominican Province (New York: Benziger Bros., 1947).
13. Pope Leo XIV, Magnifica Humanitas (Vatican City: Libreria Editrice Vaticana, 2026), no. 192, https://www.vatican.va/content/leo-xiv/en/encyclicals/documents/20260515-magnifica-humanitas.html.
14. Pope Leo XIV, Magnifica Humanitas (Vatican City: Libreria Editrice Vaticana, 2026), no. 199, https://www.vatican.va/content/leo-xiv/en/encyclicals/documents/20260515-magnifica-humanitas.html.
15. Catechism of the Catholic Church, 2nd ed. (Vatican City: Libreria Editrice Vaticana, 1997), no. 2312.
16. Pontifical Council for Justice and Peace, Compendium of the Social Doctrine of the Church (Vatican City: Libreria Editrice Vaticana, 2004), no. 507.
17. Pope Leo XIV, Dilexi Te: On Love for the Poor (Vatican City: Libreria Editrice Vaticana, 2025), no. 9, https://www.vatican.va/content/leo-xiv/en/apost_exhortations/documents/20251004-dilexi-te.html.
18. Pope Leo XIII, Rerum Novarum: On Capital and Labor (Vatican City: Libreria Editrice Vaticana, 1891), no. 20, https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_15051891_rerum-novarum.html.
19. Pope Leo XIII, Rerum Novarum: On Capital and Labor (Vatican City: Libreria Editrice Vaticana, 1891), no. 20, https://www.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_15051891_rerum-novarum.html.
20. Catechism of the Catholic Church, 2nd ed. (Vatican City: Libreria Editrice Vaticana, 1997), no. 2316.
21. Catechism of the Catholic Church, 2nd ed. (Vatican City: Libreria Editrice Vaticana, 1997), no. 2317.
22. Pope Leo XIV, Dilexi Te: On Love for the Poor (Vatican City: Libreria Editrice Vaticana, 2025), no. 94, https://www.vatican.va/content/leo-xiv/en/apost_exhortations/documents/20251004-dilexi-te.html.
23. Pope Francis, Fratelli Tutti: On Fraternity and Social Friendship (Vatican City: Libreria Editrice Vaticana, 2020), no. 26, https://www.vatican.va/content/francesco/en/encyclicals/documents/papa-francesco_20201003_enciclica-fratelli-tutti.html.