For nearly a century, from 1898 to 1994, the United States has played an outsized role in shaping political outcomes across Latin America. Washington intervened at least 41 times to alter governments in the region, often successfully. In seventeen of those cases, intervention was direct. For many Latin American nations, the sight of the stars and stripes has been less symbolic than tangible. Paraguay is no exception.

The roots of this influence stretch back to the Monroe Doctrine, which cast Latin America and the Caribbean as part of Washington’s sphere of influence. From one perspective, it stands as one of the most consequential decisions in U.S. diplomatic history, allowing American policymakers to pursue strategic objectives while, at times, contributing to economic and political development across parts of South America. That legacy, however, sits uneasily alongside more recent geopolitical shifts, particularly after Russia’s 2014 military intervention in Ukraine, which marked a turning point in global power competition.

For today’s diplomats, understanding Latin America requires more than familiarity with policy frameworks. It demands attention to political personalities and institutional dynamics. Ignacio Arana Araya, an assistant professor at Carnegie Mellon’s Institute for Strategy and Technology, argues in his book Presidential Personalities and Constitutional Power Grabs in Latin America, 1945–2021, that U.S. policymakers often underestimate the role individual leaders play. In a region dominated by presidential systems, leadership style can shape national trajectories in ways that formal institutions alone cannot.

That blind spot has had real consequences. When Bill Clinton appointed David N. Greenlee as ambassador to Paraguay in 2000, the United States still stood as the world’s dominant power, wielding diplomacy as a tool to advance its interests and manage emerging threats. But the post-9/11 world quickly exposed the limits of that approach. In the wake of the September 11 attacks, Greenlee failed to persuade Paraguayan President Luis Ángel González Macchi to commit troops to Operation Enduring Freedom in Afghanistan.

More broadly, Greenlee appeared ill-prepared to navigate the political landscape of Paraguay. His tenure was marked by diplomatic missteps that damaged Washington’s standing. In one widely criticized episode, he publicly rebuked Paraguayan judges in Alto Paraná—figures who were actively combating drug trafficking and prosecuting leaders of transnational criminal organizations. These judges operated in the volatile Tri-Border Area, long associated with money laundering and suspected links to extremist networks. Rather than strengthening ties, Greenlee’s approach deepened mistrust.

His difficulties extended to communication. At times, his remarks betrayed a lack of cultural awareness and diplomatic precision, undermining the credibility of U.S. engagement. The result was not merely a series of awkward moments but a broader erosion of influence at a time when regional dynamics were shifting.

Those shifts became more pronounced with the rise of Hugo Chávez, whose government expanded its influence across the region. During Greenlee’s tenure, Chávez cultivated relationships with Paraguay’s political elite, including members of the Colorado Party and President Nicanor Duarte Frutos. Some of those networks, critics argue, continue to shape Paraguayan politics today.

A decade later, under Barack Obama, Washington appointed James H. Thessin as ambassador to Paraguay. Though more measured in tone than his predecessor, Thessin faced similar challenges. His handling of the 2012 political crisis surrounding President Fernando Lugo proved particularly contentious. Lugo’s removal by Paraguay’s Congress followed constitutional procedures, yet Thessin appeared to align himself with the ousted leader, raising questions about Washington’s grasp of local political realities.

The crisis unfolded amid broader concerns about governance. Lugo, like current President Santiago Peña, spent significant time abroad, often to the frustration of domestic officials. His leadership style drew criticism for its detachment, culminating in decisions such as dismissing a cabinet minister while the latter was on an official visit overseas.

In the aftermath of Lugo’s removal, Federico Franco assumed the presidency and sought to stabilize the country. His tenure coincided with regional backlash, as Paraguay faced diplomatic isolation from organizations such as MERCOSUR and UNASUR. Franco positioned himself as a defender of the U.S.-Paraguay relationship and a bulwark against the spread of Chavismo. Yet Washington’s response was muted. Thessin’s reluctance to publicly confront Venezuelan influence—including allegations that certain Paraguayan military figures maintained ties to Caracas—further underscored the gap between U.S. strategy and regional realities.

The episode revealed a recurring problem: American diplomats often arrive in Latin America without a sufficiently nuanced understanding of presidential leadership and political culture. As Óscar Arias Sánchez once observed, leadership is not about pleasing constituencies but making difficult decisions in moments of crisis. That principle has guided some of the region’s most effective leaders, even as U.S. officials have struggled to interpret or support them.

The consequences of that disconnect are not merely theoretical. Missteps in diplomacy can harden perceptions of arrogance, weaken alliances, and create openings for rival powers. In a world increasingly defined by multipolar competition, those costs are rising.

Arana Araya’s work offers a corrective. By examining the personalities, decision-making styles, and institutional strategies of Latin American presidents, he provides a framework for understanding how power actually operates in the region. His analysis moves beyond abstract theory, grounding diplomatic practice in the lived realities of political leadership.

For the next generation of American diplomats, the lesson is straightforward but often ignored: effective statecraft begins with understanding people. Without that foundation, even the most carefully crafted policies risk falling flat.