The UK's Chief of Defence Staff told the BBC that Britain faces its most dangerous period since the Cold War, driven by Russian military incursions including cyber attacks, sabotage, and unprecedented airspace violations — Russian jets entered UK airspace more times in the first five months of 2026 than during all of 2025. This warning comes as the Defence Investment Plan faces months of delays, leaving Britain with limited time to respond to the escalating Russian threat. The statement reflects broader NATO concerns about Russian testing of Western defences across the Atlantic alliance.