In a stern warning to European airports, US Transportation Secretary Sean Duffy has signalled potential retaliatory measures against Ireland over the passenger cap at Dublin Airport, drawing parallels with recent actions against Mexico and past restrictions on Dutch carrier KLM.
The Dublin Airport cap, limiting annual passenger numbers to 32m, while currently in llegal limbo, has sparked concern in the United States, with Duffy suggesting it could breach the EU-US aviation agreement. This restriction, intended to manage congestion and environmental concerns, is increasingly viewed as a trade barrier, prompting fears of transatlantic aviation tensions.
Duffy’s remarks come in the wake of the Trump administration’s decisive response to Mexico’s reduction of capacity at Benito Juarez International Airport in Mexico City. Since 2022, Mexico’s actions, including rescinding flight slots and forcing US cargo carriers to relocate, have been deemed a violation of the 2015 US-Mexico Air Transport Agreement.
In retaliation, the US Department of Transportation imposed stringent measures, requiring Mexican airlines to submit schedules for approval and restricting large passenger and cargo charter flights to the US. Duffy framed these actions as a warning to any nation exploiting bilateral aviation agreements, explicitly referencing Mexico’s “flagrant violation” as a precedent.
The US has a history of responding robustly to perceived restrictions on its carriers. Last year, similar measures were imposed on KLM over flight restrictions at Amsterdam’s Schiphol Airport, where efforts to reduce noise pollution led to slot limitations. The US viewed these as unfair, prompting bureaucratic hurdles for KLM’s US operations.
Although no explicit threat has been made against Ireland, Duffy’s comments suggest that Dublin’s cap could lead to similar consequences, such as requiring airlines to seek approval for individual flights, a move that could disrupt transatlantic travel and impact Ireland’s economy, given the US market’s significance.
The Dublin Airport Authority has acknowledged the US concerns, with a spokesperson describing the cap as “outdated and unworkable.” The Irish Government now faces a diplomatic challenge, balancing local vested interests with international trade obligations.
can duffyDuffy’s warning underscores the Trump administration’s broader scrutiny of European airports, including Schiphol’s planned reduction of annual flights from 500,000 to 478,000 starting in November 2025, which could affect US carriers like Delta, a partner of KLM. As legal proceedings continue and pressure mounts in Ireland, the threat of US retaliation looms large, potentially reshaping transatlantic aviation dynamics.
