A Coalition of the Willing, Latin American Edition
(Op-Ed Analysis) The name itself is a tell. The Monroe Doctrine’s original formulation in 1823 described itself as a “shield” — a protective barrier against European interference in the Western Hemisphere. Two centuries later, Donald Trump unveiled the “Shield of the Americas,” a 17-nation military coalition pledged to use lethal force against drug cartels. Defense Secretary Pete Hegseth has said the Monroe Doctrine is “back and in full effect.” Trump calls it the “Donroe Doctrine.” What arrived in Miami on March 7 is neither a shield nor a doctrine. It is a loyalty test.
The twelve heads of state who flew to Doral — from Argentina’s Javier Milei to El Salvador’s Nayib Bukele — share one characteristic: ideological alignment with Washington. The three countries most essential to any counter-narcotics effort — Brazil, Mexico and Colombia — were deliberately excluded. An anti-drug coalition without the world’s largest cocaine producer, its primary transit corridor, and its biggest continental economy is, as Colombia’s Gustavo Petro observed from Vienna, a shield full of holes.
The Point Was Never the Drugs
Analysts at Chatham House and the Inter-American Dialogue have pointed out what should be obvious: the Shield is not primarily an operational framework. It contains no permanent institutional structure, no secretariat, no binding mechanism for monitoring results. Juan Gabriel Tokatlian of Argentina’s Universidad Torcuato Di Tella compared it to the “coalitions of the willing” that Washington assembled after September 11 — temporary groupings where the United States defines the mission and allies volunteer to follow.
That comparison is more revealing than it appears. The post-9/11 coalitions were designed to sort the world into two categories: those who were with Washington and those who were against it. The Shield performs the same function. Its purpose is not to seize cocaine in Trinidad or dismantle labs in Honduras. It is to demonstrate that a majority of Latin American governments have chosen to align with the United States and its vision of militarized hemispheric security.
The Message to the Outsiders
The message to the excluded countries is unmistakable. Mexico’s Claudia Sheinbaum responded with calibrated defiance, reaffirming that she will never allow U.S. troops on Mexican soil while maintaining that bilateral intelligence cooperation continues. Petro went further, arguing from the UN narcotics commission that Washington had sidelined decades of shared counter-narcotics expertise — a network built with 75 countries — in favor of political theater.
But it was Brazil’s Lula who made the most striking leap. Speaking alongside South Africa’s Cyril Ramaphosa the day after the Doral summit, Lula warned that Brazil could be invaded “any day” if it fails to strengthen its defenses. He proposed a joint arms-production partnership with Pretoria, framing it as an alternative to dependence on what he called the “Lords of Arms.” The subtext is clear: the January capture of Venezuela’s Nicolás Maduro by U.S. special forces — an 18-minute raid on a sovereign nation — has shattered assumptions about the limits of American power in the hemisphere.
Two Hemispheres in One
What is emerging is not a hemisphere united against cartels. It is a hemisphere split into two blocs resembling competing security architectures. On one side: a U.S.-led coalition of conservative governments willing to accommodate American military operations, from cartel strikes in Ecuador to the seizure of a sitting president in Venezuela. On the other: the region’s largest economies, led by Brazil and Mexico, reaching outward to South Africa, the BRICS nations, and the Global South for the defense partnerships Washington is no longer offering them.
The historical parallels are not comforting. Latin America’s past is littered with ideologically sorted blocs — UNASUR, ALBA, PROSUR — that collapsed the moment the political pendulum swung. The Shield will almost certainly share their fate; Chatham House has already called it “destined to fail.” But the precedent may outlast the institution. By formalizing a military alliance sorted by ideology rather than geography or capacity, Trump is normalizing a framework in which the United States intervenes with allies and against adversaries, with no pretense of multilateral legitimacy.
The Real Risk
The most dangerous outcome is not that the Shield will destroy the cartels — it won’t. It is that it will push excluded nations toward exactly the kind of defensive posture that makes the hemisphere less stable. Lula is already talking about arms production. Sheinbaum is fortifying the principle that Mexican sovereignty is non-negotiable. Petro is building coalitions at the United Nations. None of this makes anyone safer.
The original Monroe Doctrine, whatever its flaws, at least claimed to protect the sovereignty of every nation in the Americas. The Shield of the Americas protects only those who pass the loyalty test. The question now is what happens to those who don’t.