Sir Simon Case, who stood down as Cabinet Secretary in December, made the warning in his first major interview since leaving the job
The former head of the Civil Service, Sir Simon Case, has warned that the next two decades are likely to be “dominated” by conflict between nations, as geopolitical tensions rise and the international order becomes increasingly unstable.
In his first major interview since stepping down as Cabinet Secretary in December due to a rare health condition, Sir Simon said Britain must urgently rethink its defence strategy and prepare for a prolonged period of global unrest.
Speaking to The Times newspaper, the former civil servant called for the development of alternative methods of delivering Britain’s nuclear deterrent, currently deployed exclusively via submarines on continuous at-sea patrol. He urged ministers to consider new capabilities, including land-based and aircraft-launched missiles, to ensure a more resilient and versatile deterrent system.
“In my view, you wouldn’t rely on a single system for anything,” Sir Simon said. “That’s true in many walks of life, let alone nuclear deterrence.”
His remarks come ahead of the Government’s strategic defence review – a broad reassessment of the UK’s defence capabilities in light of changing threats. Sir Simon’s call is expected to add pressure on Prime Minister Sir Keir Starmer’s Government to adopt a more aggressive stance on defence preparedness.
Describing himself as a “pessimist” about the current world trajectory, Sir Simon expressed deep concern about what lies ahead for the West and the next generation.
“As I look out on my children’s lives, the next 10 and probably 20 years is going to be dominated by this inter-state conflict,” he said. “It feels to me that we across the Western alliance need to get our skates on and be ready.”
Sir Simon’s warning echoes growing fears across NATO and Western democracies that the world is entering a new era of confrontation – not only with hostile state actors like Russia and China but also in dealing with the strategic fallout of conflicts such as those in Ukraine and the Middle East.
In a separate appearance on The General & The Journalist, a newly launched podcast by The Times, Sir Simon reiterated his belief that the UK should urgently increase its defence budget. He argued that Britain must push defence spending to 3% of GDP “as soon as possible” to ensure it remains capable of meeting modern security challenges.
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The current Labour Government, led by Sir Keir Starmer, has pledged to raise defence spending to 2.5% of GDP by 2027, with a longer-term ambition to reach 3% in the next Parliament. However, critics argue that these plans may not go far or fast enough to confront today’s threats.
Sir Simon’s extensive Civil Service career spanned over a decade, serving under seven prime ministers including David Cameron, Theresa May, Boris Johnson, Liz Truss, Rishi Sunak and finally Sir Keir Starmer. His tenure as Cabinet Secretary was marked by some of the most turbulent periods in recent British political history – including the COVID-19 pandemic, Brexit fallout, and repeated changes in national leadership.
Despite leaving public service due to health reasons, Sir Simon’s interventions suggest he remains an influential voice in Whitehall circles. His warnings may now serve as a catalyst for renewed debate around national security and Britain’s role on the global stage.
As the strategic defence review looms, Sir Simon’s stark outlook will likely weigh heavily on policymakers’ minds – particularly as the UK charts its course in an increasingly volatile world.
