Portuguese prosecutors open probe into US military use of Azores air base

Legal probe into base authorization

Portuguese prosecutors opened an inquiry into the legality of government decisions that allowed the United States military to use Lajes Air Base in the Azores during operations against Iran. The Prosecutor General's Office launched the proceedings following a formal complaint filed in April 2026 by members of the Left Bloc opposition party. Under Portuguese criminal procedure, prosecutors are bound by the principle of legality, which obliges them to open formal investigations whenever complaints present sufficient legal grounds.

Bilateral treaties and political dispute

The investigation scrutinizes the administration of Prime Minister Luís Montenegro, which granted authorization for multiple American military transit flights. Unlike neighbouring Spain, which refused similar transit permissions, Lisbon permitted US forces to conduct logistical support, drone transport, and mid-air refueling operations connected to the Middle East conflict and Operation Epic Fury. The Left Bloc contended that permitting these missions represented a gross breach of international legal standards and exceeded existing treaty boundaries.

Bilateral defense accords governing the base on Terceira island date back to 1951, with framework rules updated in a 1995 agreement allowing US Air Force access for NATO-related missions. Under these terms, Washington maintains peacetime transit access without prior case-by-case clearance, but Portuguese law requires explicit ministerial authorization once foreign hostilities commence.

Government response and Washington remarks

Foreign Minister Paulo Rangel defended the executive's actions, insisting that Portugal did not become an active participant in the armed conflict. Rangel stated that authorization was approved only after receiving direct assurances from American officials that all transit operations would be strictly defensive, necessary, proportionate, and confined exclusively to military targets. Portugal's Foreign Ministry declined further comment following the announcement of the judicial probe.

The political dispute intensified after US Secretary of State Marco Rubio publicly praised the Portuguese government during a television interview in May 2026. Rubio commended Lisbon's rapid approval of American requests on Fox News.

Some NATO countries were of great help, like Portugal, which answered 'yes' even before we formulated our question.

Strategic importance and environmental oversight

Lajes Air Base hosts the 65th Air Base Wing of the US Air Force and has served as a primary Atlantic transit hub since World War II. The strategic value of the Azores archipelago was a key factor in Portugal's invitation to co-found NATO in 1949. Beyond the judicial inquiry into flight authorisations, local officials have placed the installation under closer environmental review. In September 2026, the regional parliament of the Azores instituted an inquiry commission to assess the extent of aviation fuel contamination in soil surrounding the base, where witnesses and technical studies indicated fuel had been kept in leaking storage tanks for years.