https://en.wikipedia.org/wiki/Ireland%E2%80%93NATO_relations
In February 2015, two Russian Tupolev Tu-95 "Bear" nuclear-capable strategic bombers entered Irish-controlled airspace without permission, without forewarning, with their transponders switched off and failed to file flight plans, causing serious concern at the Irish Aviation Authority (IAA), which was forced to divert a number of civil passenger aircraft out of the path of the Russian bombers as a precautionary measure.[24] The Russian military aircraft were interrogated by RAF Eurofighter Typhoon jets scrambled from the United Kingdom, demonstrating the lack of an Irish military response and the reliance on the UK for the protection of Irish airspace.
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The reports revealed that the Irish Department of Defence, Department of Foreign Affairs and Irish Aviation Authority entered into a bilateral agreement with the British RAF, Civil Aviation Authority, Ministry for Defence and Foreign and Commonwealth Office permitting the British military to conduct armed operations inside Irish sovereign or Irish-controlled airspace in the event of a real time or envisaged threat of an aerial terrorist-related attack on Ireland or on a neighbouring country.
