Sir Richard Knighton, the Chief of the Defence Staff, told Radio 4’s Today programme that the United Kingdom faces its most serious security environment since the Cold War. He cited a surge in Russian airspace violations,cyber aggression and sabotage,and called for a rapid boost in defence spending ahead of the NATO summit on July 7.

Russian aircraft entered British airspace 30 times in the first five months of 2026

Knighton highlighted that Russian forces have breached UK airspace as many times in the first five months of 2026 as they did throughout the entire previous year, prompting the scramble of NATO fighters 700 times. The chief said the pattern shows Moscow testing the limits of European air defence and warned that “the threat from Moscow is affecting the whole of Europe.”

Cyber attacks and sabotage add a new layer to the threat

Beyond the skies, Knighton warned that Russia is “probing, challenging, and testing British defences through traditional means, cyber attacks, technology smuggling, and reckless sabotage and assassination attempts.” According to the report, a Russian drone recently struck a block of flats in Romania, injuring two people, underscoring the growing use of unmanned systems across the continent.

£28 billion defence funding gap threatens the 2030 plan

The Ministry of Defence is facing a £28 billion shortfall through 2030, a figure the chief said must be closed quickly if Britain is to sustain long‑term warfare readiness. He urged ministers to act fast, noting that the Defence Investment Plan – due before the July NATO summit – will outline how new equipment and infrastructure will be financed over the next decade.

Shadow Defence Secretary calls the spending push “extraordinary” amid war on two fronts

James Cartlidge, the Shadow Defence Secretary ,described it as “extraordinary” that senior military leaders are being asked to find cuts while the UK is engaged in conflicts in the Middle East and Ukraine. Recent polling shows the British public remains split on increasing defence outlays, a political reality that Knighton acknowledged as a “difficult trade‑off.”

What will the upcoming Defence Investment Plan actually fund?

While Knighton stressed the need for more drones and autonomous systems – citing their decisive role in Ukraine – the exact composition of the upcoming plan remains unclear. Observers are waiting to see whether the £28 billion gap will be bridged by reallocating existing budgets, new taxes, or a combination of both.