It’s the Fourth of July. You’re preparing to host a barbecue. Up and down your street, flags are snapping in the wind, as a few kids in red, white, and blue trickle home from the neighborhood parade. It’s a celebration of the United States’ independence – in all its complicated history – a day that commemorates, in a way, the country standing apart from the rest of the world.
Independence may be the theme of the day, but even a simple backyard barbecue relies at almost every turn on international law. As work like the American Society of International Law’s International Law: 100 Ways it Shapes Our Lives has shown, nearly every part of modern life – from the food we eat to the correspondence we send and receive to our ability to know what time it is – is touched by a treaty or other piece of legal architecture that enables transnational cooperation.
International law today makes headlines largely when it goes wrong, in visible failures and open conflicts, or when it is under deliberate stress, as with the January announcement of the United States’ withdrawal from numerous international organizations and treaties. Yet as leading scholars and practitioners have observed, there is also a vital body of international law that is continuing to work, thrumming along under the surface and facilitating nearly every facet of ordinary life. Just as we are not in the habit of checking the plumbing when the water is flowing, we are not in the habit of scrutinizing the systems around us when they are working.
But that doesn’t mean the pipes aren’t under strain. In an era of profound complexity and global interdependence, whatever one thinks the United States’ role should be, active civic participation requires understanding those systems and making them visible to ourselves and to each other. This includes being able to identify the systems that are working so well they remain invisible and the systems that are being tested in real time, so that we can grasp what it would mean to lose parts of the nearly-invisible architecture on which we depend.
Here, a Fourth of July barbecue offers a self-contained example of how one small, domestic scene connects to the wider world. Many of our readers will already know the law it discusses – in some cases, have written the literal book on it – and there are endless nuances, caveats, and qualifications that could be layered onto each example (and, indeed, onto the normative valence of the whole exercise). But in the spirit of good public communication, the examples that follow are meant to be entry points to, and not the last word on, any of these legal frameworks – one example of how we might talk about and recognize international law at this most American of celebrations. (Continues after the graphic …)
International Law at the Backyard Barbecue
The Forecast
The day before your barbecue, you check the forecast. The holiday afternoon will be bright and clear: perfect for grilling. Tomorrow’s weather depends on atmospheric systems currently brewing all over the world, and the fact that this information can be distilled into a pinpoint prediction for your backyard is a feat of global cooperation. No country can see the weather coming without data from others’ skies, and under the Convention of the World Meteorological Organization (WMO) of 1947, nearly every nation contributes its observations – such as readings from satellites, ocean buoys, and weather balloons – into a common pool, and draws what it needs from the whole. (That was one reason for concern about a recent Trump administration proposal to dismantle ocean sensors: it would have reduced the quality of data feeding the system, although it would not have changed the legal architecture – but, in any event, the sensors have been saved, at least for now.)
The WMO is a specialized United Nations agency, part of a set of technical and scientific agencies that maintain global standards necessary for cooperation on everything from managing the world’s airwaves to passport recognition. Even as the United States is withdrawing from other international agreements, it appears for the moment to remain largely engaged in and supportive of these sorts of scientific and technical standards-setters. In addition to administering global cooperation, these agencies help to keep the standards updated as practice evolves, without requiring entirely new treaties to respond to new technologies. The WMO’s Unified Data Policy (Res. 1, 2021), for example, facilitates global data exchange in ways that recognize what modern data technologies can actually do.
Overall, the global architecture on which weather predictions depend is working well. Confident in the forecast, you do the last of your shopping for tomorrow’s barbecue.
A Party in the Backyard
The hour of the party arrives. Guests mill around the backyard, where drinks are chilling in coolers and the grill is beginning to heat up. The coolers, grill, and patio furniture – and much of the rest of the party setup – are all possible because something, whether parts or materials or money for investment or the completed product itself, crossed at least one border so that they could get made.
Tariffs and global shipping (more on those in other entries) have grabbed headlines and play a role here, too, but cross-border deals exist in the first place because of an invisible web of international law that lets contracts function across borders. When parties sign a deal that spans two or more countries, its terms determine (either expressly or by default) which laws govern and how any dispute will be resolved – a legal architecture that makes the deal enforceable, and gives each party confidence to do business outside its own borders. Often the parties agree that if things go wrong, they will resolve it not in either side’s national courts but in arbitration, where they can choose neutral decision-makers and meet on neutral ground. Under the New York Convention of 1958, an arbitration award can be enforced, or turned into a collectable judgment, in the courts of more than 170 countries, with only narrow grounds for the local judge to second-guess it. And all of this happens on top of a legal architecture that makes cross-border disputes workable at all, providing rules for things like serving process or collecting evidence across borders.
Together, this lets businesses deal with strangers an ocean away, because it lowers the risk of being dragged into someone else’s courts. And while parts of the global supply chain today are under visible stress, this underlying machinery – the enforceability of contracts across borders – remains largely stable, allowing for a backyard party setup brought together by perhaps dozens of unseen cross-border contracts.
Chips and Dip
By now the appetizers are out, and the guacamole is going fast. The vine-ripe tomatoes are local, the avocados and limes from Mexico, and all of them bought at the local supermarket. The United States-Mexico-Canada Agreement (USMCA), the three-country treaty that replaced NAFTA in 2020, keeps most of the continent’s produce crossing the border duty-free.
The Trump administration has, famously, sought multiple times since 2025 to impose various tariffs, including on Mexico and Canada, its USMCA trading partners. Despite some successful legal challenges to the first round of tariffs, later tariffs may stick, but Mexican avocados remain exempt because of their particular classification within USMCA’s agricultural products framework.
That framework, however, is not guaranteed indefinitely. USMCA includes a review and renewal process; on July 1, a critical deadline passed in which the United States opted not to renew for another 16-year period. Without that renewal, there is effectively a long and slow winding down: USMCA will stay in effect for another decade, so long as no country withdraws, but each year will see another review that could cause substantial renegotiation of terms. As long as they remain in effect, those terms are still binding: the international law that facilitates your duty-free avocados is just as real as that holding up the forecasts and the backyard setup. But it rests on a treaty more time-bound and subject to geopolitical negotiations.
Oh, and those local tomatoes? A few years ago, those might have been more likely to be from Mexico too, but the United States last year withdrew from a tomato-pricing agreement with Mexico – the Tomato Suspension Agreement – one of several factors that shifted consumption toward domestic and sent the price of tomatoes, domestic and imported, alike soaring.
Summer Vacations
Burgers and hot dogs and veggie kebabs start coming off the grill, and people fill their plates. At one table, the conversation turns to summer vacations. Plenty of people are choosing to stay close to home, but a few are back from international trips that included flights over one or more country’s borders.
Every country has complete and exclusive sovereignty over the airspace above it, which means that in theory, a plane cleared to fly out of the United States on a transatlantic flight to Germany, passing over Ireland, the United Kingdom, and Belgium, would need permission to enter the airspace of each. But under the Chicago Convention of 1944, 193 contracting parties have agreed to certain permissions that allow each other’s aircraft to cross through their skies.
These permissions can and sometimes are rescinded, including mutual closures of Russian and Western countries’ airspace following Russia’s full-scale attack on Ukraine in 2022. And escalating conflict in the Middle East is also pushing airlines to a narrower band of flight paths. But they can adjust their routes as needed in part because of the flexibility the Chicago Convention provides.
The Group Photo
After dinner, someone calls for a group photo and everyone crowds in along a fence festooned with red-white-and-blue bunting. Someone shares the photo in the group chat, and within minutes the rest of the guests are sharing it with their own friends and family, some of whom are abroad. People send it in a variety of ways – some connected to the house wifi, some on cell data, across a variety of messaging apps – but however it is sent, the photo, like around 99 percent of international internet traffic, relies on a vast network of undersea cables to be delivered at near-instantaneous speed around the world.
For all that the world runs on these cables, the law protecting them is remarkably thin, relying primarily on the 1884 Convention for the Protection of Submarine Telegraph Cables (Paris Convention), which describes as a punishable offense deliberately or negligent damaging the cables and mandates a $500 fine. Someone who unintentionally damages cables likewise has to bear the costs of repair, not to exceed $500 – in both cases, numbers that are absurdly low to deter actors in the modern world. (In the United States, the penalty was long pegged to that number but recently increased to $5,000 under domestic law.)
Article 113 of the U.N. Convention on the Law of the Sea (UNCLOS), to which the United States is not a party, also asks member States to criminalize damaging the cables, but as a practical matter, there are few transnational enforcement mechanisms with teeth, and recent incidents reveal the cables’ vulnerability. In 2024 and 2025, several Red Sea cables were cut, noticeably impacting communications between Asia, Africa, and Europe, and analysts note that undersea cables could also be a likely target in brewing geopolitical conflicts, such as between China and Taiwan.
For now, however, the photo travels lightning-fast around the world, and soon phones are lighting up with heart emojis and replies as messages return across the same network of cables.
Fireworks and Gas Prices
As it gets dark, fireworks start going off, and you and your guests join neighbors in the street to watch. Over 90 percent of fireworks come from China, and like other goods that arrive by sea, they move across the oceans under a body of law anchored by UNCLOS. As noted above, the United States hasn’t joined the Convention, but certain principles within it, including the freedom of navigation, are so widely accepted by the world’s countries that they are considered customary international law, as binding as treaties and applicable to all countries.
Among the rules are that a strait used for international navigation may not be closed off, which was tested almost to breaking earlier this year. During the conflict between the United States, Israel, and Iran, passage through the Strait of Hormuz, the critical passage between Iran and Oman, was repeatedly thrown into doubt, including at one point by a U.S. enforcement of a blockade in violation of article 2(4) of the U.N. Charter. Because the Strait is a crucial point for energy transportation, its closure sent gas prices skyrocketing, shaping some of the decisions about summer travel plans you and your guests were discussing earlier in the evening. A recently negotiated memorandum of understanding between the United States and Iran includes the guarantees of safe passage required by international law and has allowed global trade to flow through the Strait once again, though not without continued flare-ups – a reminder that the sea lanes stay open only so long as the law keeping them open holds.
Beneath the starry sky, with the last of the fireworks smoke still hanging in the air, the talk turns to plans for the rest of the weekend – and, this year, to the price of getting anywhere.
* * *
The guests have departed and you begin cleaning up to the sound of families laughing and setting off the last of the small firecrackers in the street. The moments that stay with you from tonight are small and personal, and yet they were made possible by systems that connect you to people thousands of miles away, and across decades.
From the weather forecast to the fireworks, the day rested on the international legal architecture that facilitates peace, trade, and cooperation. Occasionally a strain on that architecture causes those underlying systems to peek through – as with the talk of gas prices at the end of the night – but much of it remains invisible precisely because it’s working. Life continues atop a web of treaties, managed commons, and institutions built deliberately, over decades, and often by the United States itself. This remarkable achievement is not guaranteed, and as shown, it is not necessarily self-sustaining.
This is not to say today’s systems are without problems, and there are a range of possible reforms to explore. Almost everyone, regardless of political valence, would object to something in how the current systems work, and those objections deserve to be taken seriously. But to evaluate the system, we first must see it – and without an understanding of its fullness and complexity, frustrations too often get channeled into a “burn it all down” critique.
Washing dishes from your kitchen window, you watch people spilling in and out of houses in the lamplight. At a moment when the United States is pulling back from the world it helped build, July 4th offers a moment for turning outward: toward our neighbors, and toward the rest of the world with whom we are linked.
