The risks and threats are greater than I have known since the Cold War
Britain's most senior military officer has issued a sobering assessment: the United Kingdom now faces a convergence of threats — Russian airspace incursions, cyber operations, sabotage, and the spectre of prolonged great-power conflict — that together constitute the most dangerous strategic environment since the Cold War. Sir Richard Knighton's warning is not a forecast but a present-tense reckoning, drawn from the lived acceleration of provocations in 2026 alone. At its core, this moment asks a civilisational question that comfortable democracies rarely pose to themselves: what are we willing to sacrifice to remain secure?
- Russian strategic aircraft have probed UK airspace in five months as many times as they did in all of 2025 — a pace that suggests deliberate boundary-testing, not routine manoeuvre.
- The threat is not confined to the skies: cyber attacks, sabotage, and assassination attempts signal an adversary waging war across every domain simultaneously, straining defences built for a simpler era.
- Ukraine has demolished the assumption that modern conflicts are short and contained, forcing Britain to reorient its entire military posture toward the possibility of years-long, resource-intensive war.
- A Defence Investment Plan, long delayed since autumn 2025, is now promised before NATO's July 7th summit — but funding decisions will require painful trade-offs that ministers have so far deferred.
- Drones and autonomous systems are no longer future concerns; the window to master them is narrowing, and Britain's technological edge must be actively defended rather than assumed.
Britain's Chief of the Defence Staff, Sir Richard Knighton, sat down with the BBC this week to deliver a professional judgment rather than a political warning: the United Kingdom is living through its most dangerous period since the Cold War. The threats are real, he said, and they are multiplying.
The most visible sign is Russian military activity. In the first five months of 2026, Russian strategic aircraft have probed UK defences as many times as they did throughout all of 2025. Knighton described these incursions as deliberate provocations — designed to test response times and find weakness — and warned that Russia is edging toward a line whose crossing would carry unknowable consequences.
Yet the danger extends well beyond radar. Russia is simultaneously pursuing cyber operations, sabotage, and assassination attempts against Britain — what strategists call a multi-domain assault, attacking across every available avenue at once. Defences built for a single kind of war must now contend with several happening in parallel.
Ukraine has also rewritten the assumptions underpinning British military planning. Years of preparing for short, contained interventions have given way to the recognition that great-power conflicts can grind on for years, consuming resources at a pace peacetime budgets cannot sustain. "We need to spend more on defence and do it faster," Knighton said plainly, acknowledging that ministers face difficult trade-off decisions ahead.
Defence Secretary John Healey has committed to publishing a Defence Investment Plan before NATO's July 7th summit — a document repeatedly delayed since autumn 2025 that will outline how Britain funds new equipment, infrastructure, drones, and autonomous systems over the next decade.
Knighton's closing message was unambiguous: the comfortable assumption that defence is a background concern managed by professionals while society focuses elsewhere no longer holds. The most dangerous period since the Cold War is not approaching — it is already here.
Britain's most senior military officer sat down with the BBC this week to deliver a stark assessment: the country is entering its most perilous period in living memory, a stretch of vulnerability that exceeds anything experienced since the Cold War ended. Sir Richard Knighton, the Chief of the Defence Staff, framed the warning not as speculation but as professional judgment drawn from decades in uniform. The threats are real, he said, and they are multiplying.
The most visible sign of escalation is Russian military activity in British airspace. In the first five months of 2026 alone, Russian strategic aircraft have probed UK defences as many times as they did throughout the entirety of 2025. That acceleration matters. It signals not just increased aggression but a testing of boundaries—Russia, Knighton suggested, is edging toward a line it has not yet crossed, and the consequences of crossing it are unknowable. The incursions are not random; they are deliberate, measured provocations designed to measure response and find weakness.
But the threat extends far beyond what radar can detect. Russia is attacking Britain through multiple channels simultaneously: traditional military means, certainly, but also cyber operations, sabotage, and assassination attempts. This is what military strategists call a "multi-domain" threat—an adversary working across every possible avenue of attack at once. The UK's defences, built over decades to handle one kind of war, must now contend with several happening in parallel.
This reorientation represents a fundamental shift in how Britain must think about its armed forces. For years, the military prepared for short, contained conflicts—interventions measured in months, with clear endpoints and limited scope. Ukraine has shattered that assumption. The war there has demonstrated that modern great-power conflicts can grind on for years, consuming resources at a pace that peacetime budgets cannot sustain. Britain must now prepare not for a sprint but for a marathon, and that requires money—more of it, and faster than current plans allocate.
The government has acknowledged this reality. Defence Secretary John Healey has committed to publishing a Defence Investment Plan before NATO's summit on July 7th, a document that will outline how the UK will fund new equipment and infrastructure over the next decade. The plan has been delayed repeatedly since it was first promised in autumn 2025, but the urgency is now undeniable. Knighton made clear that he believes ministers understand the stakes and are moving to increase spending, though he acknowledged the difficulty of the choices ahead. "We need to spend more on defence and do it faster," he said. "The challenge for ministers is to make those difficult trade-off decisions."
The nature of future conflict itself is shifting. Drones and autonomous systems will play an increasingly central role in warfare, Knighton warned. These are not distant possibilities but near-term realities that the military must master now. The technological edge that Britain has long relied upon cannot be taken for granted; it must be actively maintained and upgraded.
Knighton's message to the country was direct: this is not a moment for complacency or business as usual. The risks are greater than they have been in decades. Society itself may need to adjust its priorities and expectations. The comfortable assumption that defence is a background concern, something to be managed by professionals while civilians focus on other matters, no longer holds. The most dangerous period since the Cold War is here, and it demands a different kind of attention from everyone.
Notable Quotes
This is the most dangerous period that I have known— Sir Richard Knighton, Chief of the Defence Staff
We need to spend more on defence and do it faster. The challenge for ministers is to make those difficult trade-off decisions— Sir Richard Knighton
The Hearth Conversation Another angle on the story
When he says Russia is "crossing a line," what line exactly does he mean? Is there a formal boundary, or is this more intuitive?
It's intuitive but real. There are unwritten rules between nuclear powers—you probe, you test, but you don't actually strike. He's saying the frequency and boldness of these incursions suggest Russia is getting bolder about where that line sits. If they miscalculate, or if Britain responds too forcefully, you could have a direct military confrontation between NATO and Russia.
Why does he keep emphasizing that this is the worst he's personally known? Isn't that just rhetorical?
No. He's been in the military for decades. He lived through the post-Cold War period when the threat felt manageable, when Britain could focus on smaller interventions. He's saying something fundamental has changed in the threat environment itself, not just in his perception of it.
The multi-domain attacks—cyber, sabotage, assassination—those sound almost like a different kind of war entirely.
They are. It's below the threshold of traditional military conflict but designed to weaken you from within. You can't respond to a cyber attack the way you respond to an aircraft incursion. It's asymmetric, deniable, and very hard to defend against comprehensively.
Does he actually believe the government will fund what's needed, or is he being diplomatic?
He says he's confident, but he's also being realistic. He knows ministers face trade-offs. He's not saying they'll get everything they ask for. He's saying they understand the problem and are moving in the right direction—but faster and more would be better.
What changes for ordinary people if Britain actually prepares for a prolonged great-power conflict?
That's the question he's raising without fully answering. It could mean higher defence spending, which means less for other priorities. It could mean different civil defence preparations. It could mean a shift in how people think about national security. He's saying society needs to wake up to the fact that this isn't theoretical anymore.