Tiffany Comprés, a leading international disputes attorney, co-chairs the Pierson Ferdinand International Disputes and Practices group. With extensive experience representing U.S. and international companies in arbitration and litigation, she specializes in the complex legal terrain of agriculture, food, logistics, distribution, heavy machinery, and energy. Among just 51 attorneys board-certified in International Law by the Florida Bar, Comprés has earned recognition as a rising star in her field.

Her expertise in global trade law—particularly in frameworks like the UN Convention on Contracts for the International Sale of Goods (CISG) and the Perishable Agricultural Commodities Act (PACA)—positions her as a crucial voice on the legal and dispute resolution challenges that businesses face in an increasingly volatile trade environment.

Amid mounting tariff uncertainty, Comprés underscores the need for businesses to rethink contract terms and compliance strategies. She examines the World Trade Organization’s weakening enforcement mechanisms, the role of Incoterms in cost allocation, and the escalating risks of trade wars. Additionally, she highlights the legal ambiguities surrounding presidential tariff authority and the resulting surge in arbitration cases. As global trade governance remains in flux, businesses must navigate a landscape of shifting policies and unpredictable economic conditions—where missteps can have profound financial and legal consequences.

Scott Douglas Jacobsen: Thank you for joining me today. How do reciprocal tariffs impact international trade relations and global market dynamics?

Tiffany Comprés: I’m a lawyer, so I can only speak to that in a limited fashion. But certainly, they have broad impacts.

For example, consider steel and aluminum tariffs. A tariff on those products has effects across many sectors of the economy. The company importing the product will either absorb the cost or pass it down to consumers. Suppose the U.S. imposes tariffs on Canadian steel and aluminum, for example. In that case, the concern is that American manufacturers using those materials will face higher costs, which could lead to higher consumer prices.

As a response, Canada could impose counter-tariffs—a reciprocal measure that affects U.S. exports to Canada. This kind of tariff escalation can create ongoing disputes, with tariffs increasing or changing continuously. It can also extend beyond the initial products targeted, affecting other sectors of the economy.

And that’s just in a bilateral trade relationship. Regarding multilateral trade relationships, particularly in the World Trade Organization (WTO) framework, reciprocal tariffs can trigger broader disputes. With Trump proposing reciprocal tariffs, the risk is that multiple countries could impose retaliatory measures, leading to widespread trade disruptions.

Historically, trade wars have had severe consequences. The Smoot-Hawley Tariff Act of 1930, which imposed high import tariffs, led to significant retaliatory tariffs from other nations. This exacerbated the Great Depression by reducing global trade.

Jacobsen: What legal challenges do reciprocal tariffs present for cross-border transactions?

Comprés: Several. I have clients calling me, asking what they should plan for.

In my practice, I work with many importers and exporters of fresh fruits and vegetables—products that typically do not have tariffs due to trade agreements like NAFTA (now USMCA). If reciprocal tariffs are applied unpredictably, businesses that rely on established pricing models and supply chains could face significant disruptions.

Legal challenges include:

Contract disputes: If a tariff is suddenly imposed, existing contracts may not account for the additional costs, which can lead to litigation between suppliers and buyers.

Compliance with international trade agreements: Companies must navigate whether tariffs violate agreements under the WTO, USMCA, or bilateral treaties.

Supply chain restructuring: Businesses may need to shift suppliers or renegotiate contracts, which can lead to further legal complications.

Ultimately, reciprocal tariffs introduce uncertainty, and uncertainty is a risk in trade law.

So this is an entirely new game for this industry. Companies need to set up their accounts to pay tariffs, which they are not used to. They need to start factoring that into their operations. Can they absorb the cost?

How do they shift the cost? In international trade, there are terms called Incoterms, which serve as standardized contractual guidelines for assigning responsibilities between buyers and sellers. Incoterms do not decide anything on their own—rather, the parties involved in the transaction agree on an Incoterm, which then governs key responsibilities like insurance, freight costs, and, importantly, who is responsible for paying tariffs.

One thing I expect companies to do now is start reviewing their contracts carefully. Many terms they previously took for granted—because they never had to worry about tariffs—are now becoming critical points of negotiation.

For example, a common Incoterm is FOB (Free on Board), which means responsibility for the product transfers at the port of export. Under this arrangement, the importer is typically responsible for paying the tariffs. However, suppose a company shifts to a Delivered Duty Paid (DDP) term, where responsibility stays with the exporter. In that case, the exporter must cover the tariffs.

Sometimes, businesses do not pay close attention to these details because Incoterms are often represented in contracts by just three-letter abbreviations. Suppose companies have repeatedly used the same template agreements without considering the tariff implications. In that case, they may need to re-evaluate their contract structures. Otherwise, this could slip under the radar until someone realizes, “Wait, maybe we should change that.” Renegotiating contracts may become necessary.

I also advise clients to diversify their sourcing as much as possible to spread tariff risk. Of course, not all products can be sourced from multiple places. In agriculture, for instance, certain crops are available only in specific regions at certain times of the year. In the United States, we expect to have mangoes year-round, even though they naturally grow only during certain seasons. This demand creates additional trade complexities when tariffs are introduced.

My biggest concern is that this could lead to an ongoing cycle of tariff escalations, in which one country raises tariffs, another responds, and the cycle continues indefinitely.

The second concern is that this is the broadest application of reciprocal tariffs we have ever seen. Historically, reciprocal tariffs have been implemented on specific products or sectors. However, in the February 13 memorandum outlining the Fair and Reciprocal Trade Plan, the definition of “reciprocity” is far-reaching. It suggests that tariffs should be matched product by product, country by country.

For example, if France imposes a 10% tariff on U.S. cars, then under this framework, the U.S. would match it with a 10% tariff on French cars—instead of the current 2.5% tariff. This shift fundamentally changes trade relations and could lead to widespread retaliatory measures from trading partners.

But the memo describes reciprocity in a much broader sense than just matching tariffs. It talks not only about the actual tariffs applied but also about other trade barriers, such as taxes, regulations, subsidies, and currency policies that affect trade terms. That’s a very broad scope.

The memo also sets a 180-day turnaround time for presenting recommendations to the president. However, it’s unclear whether this means actual tariff numbers must be determined within that time. If so, that would be an incredibly tight deadline.

Given the significantly reduced federal workforce, the ability to conduct a comprehensive and in-depth analysis in such a short time seems unrealistic. I don’t see how they can do this properly without cutting corners. The administrative burden alone is going to be enormous.

This presents challenges not only in implementation but also in enforcement. For example, one of the earlier executive orders aimed to eliminate the de minimis exception. The de minimis rule allows low-value shipments, such as small online purchases under $800, to enter the U.S. without duties. The reason for this rule is largely administrative efficiency—it would be a logistical nightmare to process duties on every single small package.

However, after the rule was eliminated, it didn’t last long. The U.S. does not have enough customs officers to inspect every package and assess duties. Now, with reciprocal tariffs, we are asking customs officials to determine duty rates for every country—a monumental task.

If eliminating the de minimis exception failed due to staffing shortages, I don’t see how this plan can be effectively enforced. Other countries frequently change their tariffs, so this is not just a one-time adjustment.

If we’re serious about maintaining this reciprocal tariff policy, then every time another country adjusts its tariffs, regulations, or subsidies, the U.S. would need to respond. This would add a constant regulatory burden to an already overburdened system.

Jacobsen: Initially, several countries set a February 1 deadline for implementing these tariffs. However, negotiations—particularly with Mexico and Canada—led to a last-minute extension. Was this extension driven by a legitimate policy rationale, or was it more about optics?

Some reports suggest it was largely a public relations move. Certain agreements that emerged during negotiations involved actions already in the pipeline but were reframed as part of the bargaining process. Regardless, the outcome was a temporary, one-month delay in the tariff deadline. Yet, the fundamental uncertainties remain: How will this policy be implemented? Is it truly enforceable? And how will businesses navigate the instability?

From a legal standpoint, when a February 1 deadline looms for tariffs at a dramatic, double-digit rate, how do legal scholars begin to assess the implications? And what happens when that deadline is abruptly extended by a month? As you pointed out, when a major policy shift is imminent, every detail is scrutinized with heightened urgency.

Comprés: The first and most fundamental legal question is: under what authority is the president implementing these tariffs?

The president used a different legal strategy with those particular tariffs—invoking his emergency powers.

His justification was based on national security concerns, specifically tying it to the drug trade and fentanyl trafficking. That rationale made much more sense in the case of Mexico than it did for Canada.

There’s a significant disparity in the volume of fentanyl seized at the Canadian border versus the Mexican border. I have some figures here—hold on.

Here we go: 43 pounds of fentanyl were seized at the Canadian border last year and 22,000 pounds came through Mexico.

So, using fentanyl trafficking as the legal basis for tariffs was far more justifiable for Mexico than for Canada.

However, my concern with reciprocal tariffs is different. I don’t think the date change for the Mexico-Canada tariffs is legally significant because of the legal authority under which they were imposed. Since the legal basis is emergency powers, a one-month delay does not fundamentally change the lawfulness of the tariffs.

I’m not deeply immersed in the specific scholarly debates on that particular point, so there may be other perspectives. However, once the president invokes emergency powers to impose tariffs, the exact deadline is not necessarily a major legal issue.

But with reciprocal tariffs, is it a different legal question? The legal foundation for reciprocal tariffs is far less clear.

With Mexico-Canada tariffs, even though the scope of the president’s power under emergency authority is debatable, the precedent for using it exists. But reciprocal tariffs raise a completely different question:

Does the president even have the legal authority to impose them?

Trade policy is explicitly assigned to Congress under the U.S. Constitution. Congress holds the power to regulate tariffs and foreign trade. So, does the president need congressional approval?

Maybe.

A possible legal argument under Section 338 of the Tariff Act allows the president to impose new and additional duties on imports from countries that discriminate against U.S. exports.

However, this provision has never been used as the president proposes. It was not originally intended as a tool for broad reciprocal tariff implementation.

So, the legal justification for reciprocal tariffs remains an open question—and we could very well see legal challenges if they are implemented without Congressional approval.

It’s a clear WTO violation.

Under WTO rules, we must maintain our tariffs within pre-agreed rate levels. This also contradicts the Most Favored Nation (MFN) principle under which the U.S. has operated since 1923.

The MFN principle ensures that U.S. tariffs on imports remain identical for all WTO member countries, except in specific cases—such as goods deemed unfairly traded (e.g., anti-dumping duties). Imports from free trade partners with whom we have separate agreements.

As a result, most countries lowered their tariffs to participate in free trade, leading to global economic integration. This movement toward trade liberalization was formally memorialized in 1934 through the Reciprocal Trade Agreements Act.

However, the WTO has been severely weakened, largely because the U.S. blocked the appointment of appellate judges to its Dispute Settlement Body.

Without a functioning dispute resolution system, WTO rules become unenforceable.

If a country violates WTO rules but has no legal mechanism to resolve disputes, then what is the point of the system? It creates a frail and weakened position for global trade governance. This breakdown—combined with the proliferation of free trade agreements (FTAs)—has led countries to negotiate trade deals outside the WTO framework.

That’s why we now have regional and bilateral agreements like USMCA and the Trans-Pacific Partnership (TPP). There are now thousands of these trade agreements in place. Some are bilateral (between two countries) and some are multilateral (between multiple nations).

This parallel trade system has developed for nearly a century. Still, the rule of law governing international trade has become increasingly fragile.

This shift is largely due to the U.S. reconsidering its role as the global leader—not just diplomatically and politically but also in trade.

So, trade, diplomacy, and global leadership are deeply interconnected. They are not separate issues—they all influence one another.

Jacobsen: In today’s global economy, some companies operate strictly within domestic markets, while others engage in cross-border trade. But we also live in an era dominated by multinational corporations, where jurisdictional complexities can arise even in seemingly straightforward bilateral trade relationships.

You mentioned earlier that regulatory challenges emerge even in cases involving just two nations—such as a shipping vessel moving between Canada and the U.S. or Norway and the U.S. When that vessel enters international waters, its cargo falls outside the direct jurisdiction of any single country. How does that legal limbo shape trade regulations?

Expanding this to a broader scale, in a multinational or multilateral trade context—particularly for multinational corporations—how do tariffs add further layers of complexity? Do they make international trade law more difficult to navigate, or do they introduce new regulatory risks that companies must anticipate?

Comprés: Well, to give you just one example of how tariffs can disrupt global supply chains:

Most of my clients deal in fruits and vegetables. It’s one product—a mango or a bunch of grapes. You grow it, and that’s it. There’s no complex manufacturing process and no 25,000 components like those in a car or an iPhone. Now, think about something like an iPhone or a car.

A single device or machine has components sourced from many different countries. Some components might be manufactured in Country A, but the fabrication process could occur in Country B.

So, components come from 10 different countries, are assembled in an 11th country, and then sent to a 12th country for final integration before reaching the U.S.

That’s when things get complicated.

Jacobsen: How do tariffs apply in these cases?

Comprés: A product’s country of origin determines the tariff rate under U.S. tariff rules.

The country of origin is where it was grown for simple goods, like oranges. If you repackage the orange, it doesn’t matter—it’s still an orange, and its country of origin remains the same.

However, tariff classification follows the substantial transformation rule for complex manufactured goods.

This means that the final country where the most significant transformation occurs is considered the country of origin—not necessarily where the raw materials or components were sourced. I’ve been advising clients who deal with complex products to rethink their supply chains.

They should strategically restructure operations so that the substantial transformation occurs in a more favourable location with lower tariffs.

However, companies can’t easily relocate their factories if tariff policies keep changing.

It’s not like picking up and moving a store—it’s a massive logistical and financial challenge to close a factory in Country A and open another in Country B.

This ties back to your earlier question about the 30-day delay. The greater impact isn’t purely legal—it’s about economic stability. Business thrives on predictability. When expectations are clear, companies can manage their finances, plan investments, and forecast revenue.

However, tariff uncertainty creates a chaotic environment. Companies hesitate to act, delaying new product launches and postponing investments because the return on investment becomes unpredictable.

They don’t know what tariffs to pay, making profit margins uncertain. And in some cases, tariffs can be so high that they function as a de facto tax on companies.

Jacobsen: How can dispute resolution mechanisms under the UN Convention on Contracts for the International Sale of Goods (CISG) address tariff-related conflicts that, from what you’re saying, maybe inevitable?

Comprés: I’m fairly certain there will definitely be some of that. However, the CISG doesn’t have its dispute resolution mechanism, like an arbitration system. Instead, it provides rules on contract breaches and contract interpretation.

One key legal issue—which may be a bit dry but is important—is how the CISG handles contract interpretation differently from U.S. contract law.

In the United States, contract law follows the “four corners rule.”

Courts don’t look beyond the document if a contract is clear. The only time outside evidence is allowed is when the contract is ambiguous and its meaning cannot be resolved from the text alone.

But under the CISG, there’s no such rule.

Parties can introduce external negotiations and conversations to help interpret the contract. This means that a company could try to argue that an agreed-upon trade term—like FOB (Free on Board)—was never actually intended that way.

Would that argument hold up? I don’t think so. If a contract has always been used a certain way, the counterargument would be that usage and custom determine its meaning.

That said, I wouldn’t rule out companies trying to use CISG rules to avoid high and damaging tariffs. While unlikely to succeed, some unique contexts might allow it to work.

We are already seeing a huge increase in international arbitration over the past 10 to 20 years. That trend is only going to continue.

I also wouldn’t be surprised if we start seeing state-to-state arbitration, where countries challenge tariffs under trade agreements like the USMCA. For example, China has already filed a WTO complaint over tariffs.

Jacobsen: Could that case move forward?

Comprés: It might pass the first stage, but it won’t reach appeal—or, if it does, it will sit in limbo indefinitely. The reason? The WTO Appellate Body isn’t functioning because the U.S. has blocked the appointment of judges.

So, even if China wins in the first instance, the U.S. can appeal, and the case will remain unresolved because there is no appeals court to hear it. This is something we will see more of as trade tensions continue.

Jacobsen: Thank you. I appreciate your time, Tiffany. It was nice to meet you and thank you for your expertise.

Comprés: Oh, you’re welcome! It’s a nerdy topic but a good one.