Portugal investigates the legality of the U.S. use of the Lajes air base in the war with Iran

Portuguese prosecutors have opened an investigation into the legality of the authorisation that the centre-right government gave the United States to use the Lajes air base in the Azores during the conflict with Iran, as Reuters reports, referring to a complaint filed by the opposition Left Bloc party.

The long-standing agreement with the U.S. allows Washington to use the base without prior authorisation in peacetime, but requires Portugal’s approval once hostilities begin. Portugal, unlike neighbouring Spain, authorised several U.S. transit flights through the Lajes base — a decision that drew criticism from left-wing opposition parties and sparked political debate over Lisbon’s role in operations linked to the conflict with Iran.

The Attorney General’s Office said the investigation was opened following the complaint by Left Bloc members, without giving further details. The Left Bloc had asked prosecutors back in April to investigate the U.S. use of Lajes, arguing that it constituted a “flagrant violation of international law”. Portugal’s Foreign Ministry declined to comment.

Foreign Minister Paulo Rangel has previously said that Portugal was not involved in the conflict and that the use of the Lajes base was in line with international law, as it was authorised only after Washington gave guarantees that any operation would be defensive, necessary and proportionate, limited to military targets.

The Lajes base, in Portugal’s Azores archipelago in the Atlantic, is a strategic transit hub for U.S. forces under a bilateral defence treaty dating back to 1951 and hosts the U.S. Air Force’s 65th Air Base Wing, supporting U.S., NATO and allied operations.