In 2016, the U.S. Department of Transportation approved and granted antitrust immunity to a joint venture between Delta Air Lines and Aeroméxico for flights between the United States and Mexico, after analyzing the full U.S.-Mexico market and 1,687 city-pair markets. In 2025, after Mexico cut capacity, confiscated slots, and banned all-cargo carriers at Mexico City’s Benito Juárez International Airport, the Department terminated the approval and immunity, reasoning that the joint venture benefited from anticompetitive conditions there and that Mexico was not honoring the open-skies agreement. The Eleventh Circuit held that the termination order was arbitrary and capricious and vacated it. The court reasoned that the Department abruptly departed, without adequate explanation, from its uniform practice of comprehensive country-pair and city-pair analysis by relying on conditions at a single airport handling about 21 percent of U.S.-Mexico flights, even though the same statutory standard governs approval and continued approval. The Department also failed to treat like cases alike, because it made open-skies compliance at Mexico City a prerequisite while it had approved two U.S.-Japan joint ventures at Tokyo’s Haneda Airport, which was carved out of that open-skies agreement. Judge Rosenbaum concurred only in the judgment, agreeing with the unequal-treatment rationale but arguing that a withdrawal of an existing approval need not replicate the comprehensive analysis required for a new application.