On Wednesday, President Trump stood before the United Nations General Assembly, in part, to defend reinstated sanctions on Iranian trade goods. Those sanctions had been lifted under the 2015 nuclear deal signed by then-President Barack Obama, but were reinstated by Trump last month. The decision will impact many large-scale Iranian industries, from carpets and cars to comestibles. But one crop in particular reveals the sanctions’ international impact, and the broader consequences politics have on what, and how, we eat: the pistachio.

Today, American-grown pistachios are a lucrative industry, heralded across the globe. Stripped of context, it’s tempting to see pistachios as a success made in the U.S.A. But the underlying history is more complex. In that story, the pistachio serves as a small symbol of how our histories are shared—and how our fates are intertwined.

On the morning of November 4, 1979, hundreds of Iranian medical and engineering students—described in one account as “geeks with guns”—scaled the walls of the American embassy in downtown Tehran, taking 66 diplomats and workers hostage. The takeover was in reaction to the United States’ continued support of the recently deposed Shah. Mohammad Reza Pahlavi, a pro-Western autocrat, who seized power in 1953 with the support of the CIA—a move to reestablish Western influence over Iran’s sizeable oil revenues. The Shah and his family had fled the country for Egypt in the wake of the Iranian revolution, but in late October of 1979, President Jimmy Carter allowed Pahlavi to enter the United States for medical treatment. This entry, perceived as Western support for the toppled regime, was the tipping point for the students who stormed the embassy.

Outcry from the American public over the hostage crisis reached a fever pitch by April of the following year, exacerbated by a botched military attempt to rescue the hostages. In response, Carter announced a full trade embargo on Iranian goods, including the popular rosy pistachios.

The remaining 52 hostages were set free in January 1981, just minutes after Ronald Reagan was sworn in as president. Although the sanctions were ultimately lifted as part of the conditions of the hostage release, global pistachio production had been irreversibly upended. According to researchers at the University of California, Davis, Fruit and Nut Information and Research Center, pistachios became “the single most successful plant introduction to the United States in the twentieth century.”

Pistachios originated in south central and southwestern Asia, where the nuts are believed to have first grown wild. A member of the cashew family, they were used for thousands of years as food, medicine and an aphrodisiac. The small trees were domesticated and planted on the slopes of Afghanistan and southeastern Iran as early as 6000 B.C. and, subsequently, were cultivated throughout the Persian Empire. They gradually expanded west, becoming part of Italian and Spanish cuisines by 30 A.D., and reached southern European, North African and Chinese palates as a result of trade along the Silk Road in the first millennium A.D.

Centuries later, in the mid-1800s, pistachios hit the United States. Local merchants attempted to sate the appetites of Middle Eastern immigrants in New York City and surrounding areas by importing the nuts into the country. The pistachio’s ties to America deepened in 1904 when trees were planted on domestic soil for the first time by the U.S. Department of Agriculture (USDA). The collection, however, was part of a larger effort to establish a collection of Pistacia species intended for research, not commercial, purposes.

At the time, Iran was the world’s uncontested leader in pistachio production. But the shift in market dominance that transpired under the Carter administration was partially seeded in 1929, when botanist William E. Whitehouse traveled to the Middle East to collect pistachios. Whitehouse, a member of the now-defunct plant exploration division of the USDA, scoured Persia to find pistachios that could thrive domestically. Months later, he returned to the United States with 20 pounds of samples he hoped would be viable. The nuts flourish in regions with long, dry summers and mild winters and were, therefore, planted in the Sacramento Valley, an area considered one of the more fertile agricultural regions in the world.

It took years for Whitehouse to test his selections. (Pistachio trees mature in five to eight years, but they don’t reach peak production until 15 or 20 years in.) He carefully tended to the pistachio fruits, drupes that cluster like grapes on a vine as they slowly transform from a pale greenish color to a yellow tinged with pink. But out of the thousands he collected, only one small nut was viable.

Nearly half a century later, in 1976, the first commercial crop of Kermans was harvested in the United States, weighing in at 1.5 million pounds. Known for large, meaty nuts and shells with a wide split, the Kerman is still our nation’s dominant cultivated variety. In 2017, the harvest reached nearly 1 billion pounds—all descended from a single Iranian nut weighing one-fortieth of one ounce.

Embargoes have continued to be used as instruments of foreign policy and have been a source of both challenge and relief for domestic producers. For American pistachio farmers, the easing of sanctions in 1986 was a turning point: The United States resumed trade with Iran, and Persian pistachios made their way back onto store shelves just as American trees were reaching peak maturation. This competition precipitated a new layer of sociopolitical drama as domestic producers and processors, worried that the imports would compromise sales of their new crop, petitioned the U.S. International Trade Commission. The federal agency agreed that Iran’s pistachio prices would pose a threat to local production and imposed a special import duty of just over 214 percent on unshelled Iranian pistachios. This protectionist antidumping tariff—“dumping” is the term for selling export goods below the cost of production in a foreign market— was renewed last June and remains in place to this day.

Sahar Nakhaei, the international relations coordinator for the Iran Pistachio Association, thinks otherwise. While she agrees that water scarcity and the deterioration of water quality present great challenges in the areas where pistachios are traditionally grown, she stresses that Iran’s output will remain robust because of expanded production into new areas.

Yet, even if the Iranian crop holds firm, producers now face renewed restrictions on exports to the United States. When President Obama lifted trade sanctions in 2016, the impact on the domestic pistachio market was modest because the antidumping duty was in effect. What did manage to find a place in U.S. markets—by way of ice cream cones, cannoli and other treats—were Iranian pistachio kernels: bits of shelled nuts used as confections that were exempt from the tariff. Roughly 1 million pounds of kernel imports are now in peril due to the sanctions Trump has reinstated.

But, regardless of how the exports are split between countries, there will always be an appetite for pistachios, says Bob Klein, manager of the Administrative Committee for Pistachios, an organization dedicated to regulating the quality of nuts. He explained in an interview with Bloomberg that “global production … doesn’t meet global demand, so all the products can find a market. It’s just going to shift around.”

Despite Trump’s push for the replacement of “the ideology of globalism” with a “doctrine of patriotism,” one thing is for certain: Were it not for Iran, the United States would not have pistachios—not as a snack or as an industry.

“The destiny of nations depends on the manner in which they feed themselves,” French politician and gastronome Jean-Anthelme Brillat-Savarin wrote in his 1825 tome The Physiology of Taste. Today, no country is self-sufficient in agricultural resources. The destiny of nations is no longer limited to the manner in which they feed themselves, but how we feed each other.