Iran last month sent an official warning to Bulgaria, demanding that it not allow American aircraft to use its airports for military operations against Tehran. The information came to light after Bulgarian MP Stanislav Balabanov published the diplomatic note dated March 18.

The note specifically protested the presence of American refueling aircraft at Bulgaria's "Vasil Levski" airport. The Iranian communication explicitly reserved the right "to take all necessary measures to protect its sovereignty, security, and national interests in accordance with international law."

Bulgarian Deputy Foreign Minister Marin Raikov subsequently confirmed the document's authenticity, attempting to ease tensions: "Bulgaria is not at war. No combat aircraft is using Bulgarian territory for military operations. We maintain normal diplomatic relations with Iran."

The case is part of a broader trend of European countries distancing themselves from American military policy toward Iran. Spain closed its airspace to US military aircraft, Italy refused landing rights for strategic bombers, and Poland rejected requests for Patriot air defense systems.

All of this points to a deepening of friction between Washington and its European allies, as countries invoke international law and the risks of regional destabilization.