87 million phones will screech with terrifying siren as ministers warn UK must be ready for conflict on home soil for first time since WW2
Every mobile phone in Britain will blast out a spine-chilling 10-second siren later this year in a dramatic test of the nation’s war readiness – as the government warns citizens to prepare for the “active possibility” of conflict on UK soil.
The chilling nationwide alert, which will reach 87 million devices even if they’re set to silent, comes as ministers unveil a stark new National Security Strategy that reads like something from the darkest days of the Cold War.
In language not seen since Churchill rallied the nation against Hitler, the government is calling for a “whole-of-society effort” reminiscent of 1945, warning that Britain faces threats from Russia, China, Iran and North Korea that could bring devastation to our streets.
‘We can no longer assume war will stay abroad’
The bombshell security document, published on Tuesday, pulls no punches about the dangers facing Britain. The years ahead will test the United Kingdom,” it warns ominously. “The direction it takes – and the decisions we take – will reverberate through the decades.”
Cabinet Office minister Pat McFadden told MPs the entire country must now be “clear-eyed and hard-edged” about threats, admitting: “We are in an era in which we face confrontation with those who are threatening our security.
The report states: “Meanwhile, critical national infrastructure – including undersea cables, energy pipelines, transportation and logistics hubs – will continue to be a target.”
Most alarmingly, security chiefs now believe Britain can “no longer assume” that conflict will remain on foreign battlefields. The strategy explicitly calls for the UK to “actively prepare for the possibility of the UK coming under direct threat, potentially in a wartime scenario”.
Your phone WILL scream – and you can’t stop it
When the emergency alert test strikes – and officials won’t yet say exactly when – prepare for chaos. The ear-splitting siren will sound for 10 seconds on every 4G and 5G phone in the country, vibrating frantically even if your device is on silent mode.
The test message will flash across screens warning: “This is a test of Emergency Alerts, a UK Government service that will warn you if there’s a life-threatening emergency nearby. In a real emergency, follow the instructions in the alert to keep yourself and others safe.”
While you can technically turn off the alerts in your phone settings, the government is strongly urging people not to – warning these messages could save your life in a real crisis.
Europe’s survival guide: 72 hours to stay alive
Britain’s alert test is part of a wider European panic about preparedness. In March, Brussels ordered all 450 million EU citizens to stockpile emergency supplies for at least 72 hours – the critical period when you’d be on your own before help arrives.
France has gone even further, distributing a 20-page survival manual to every household listing essentials like six liters of bottled water, a dozen tins of food, batteries, a flashlight, and basic medical supplies such as paracetamol and saline solution.
The French guide even includes advice on what to do in a nuclear attack – a chilling reminder of how seriously European governments are taking the threat of war.
In the EU we must think different because the threats are different, we must think bigger because the threats are bigger too,” Hadja Lahbib, the Commissioner for humanitarian aid and crisis management, told reporters.
From missiles to hackers: The nightmares keeping ministers awake
According to insiders, Whitehall recently war-gamed terrifying scenarios including missile and cyber attacks on Britain’s critical infrastructure. The results were sobering: our defences wouldn’t stop every incoming weapon, and attacks would be “likely to result in civilian fatalities”.
The strategy warns that hostile nations are developing “new chemical and biological weapons” and that “hypersonic missiles and AI-enhanced systems will be supplemented by mass-produced, low-sophistication capabilities like drones.
The document reveals our enemies are already working together, noting how North Korea is supporting Russian forces in Ukraine – proof that “hostile nations are increasingly willing to cooperate.
‘Blitz spirit’ needed again, says PM
In his introduction to the security strategy, Sir Keir Starmer invoked Britain’s finest hour, declaring: “We do not need to look too far into our history for an example of a whole-of-society effort, motivated by a collective will to keep each other safe.
The Prime Minister added: “We can mobilize that spirit again and use it both for our national security and the rebuilding of our country”.
Labour has pledged to boost defence spending to 5% of GDP by 2035 – a level of military investment not seen since the height of the Cold War – as threats mount from all directions.
When disaster strikes: What the alert has already done
This isn’t just theoretical planning. The emergency alert system has already been used in real crises:
- February 2024: Plymouth residents were evacuated when an unexploded World War Two bomb was discovered
- April 2024: Flood warnings saved lives in Cumbria
- December 2024: Storm Darragh alerts helped people prepare for devastating winds
But these were local emergencies. The nationwide test represents something far more ominous – preparation for threats that could strike anywhere, anytime.
Former spy chief: ‘Prepare for war NOW’
The government’s warnings have been echoed by security experts. Former MI6 chief Sir Alex Younger told The Independent that Vladimir Putin’s ambitions represent a “real and present danger” to Britain.
He even suggested a form of national service might be needed, warning: “This is probably more about a more creative and broader conception of what the reserves is.”
Cyber warfare expert Dr Rachel Ellehuus warned that Russia is actively “trying to redraw the map” of Europe, with unconventional attacks on infrastructure increasing by 300% in the past year alone.
The new War Book: Your survival checklist
Officials are updating the legendary “War Book” – the Cold War-era manual that detailed how Britain would function under nuclear attack. The new version reflects 21st-century threats:
What you need in your emergency kit:
- Water: One gallon per person per day for 72 hours minimum
- Food: Non-perishable supplies for at least three days
- Medicine: Essential prescriptions plus painkillers and first aid
- Power: Battery-powered radio, flashlights, spare batteries
- Documents: Copies of ID, insurance papers in waterproof bags
- Cash: Small bills in case electronic payments fail
- Communication: Know which radio frequencies to monitor
During an alert:
- Follow instructions immediately
- Stay indoors unless told to evacuate
- Monitor official channels for updates
- Don’t spread unverified information on social media
- Check on vulnerable neighbours
Can’t turn it off? Here’s why you shouldn’t try
While tech-savvy Brits might be tempted to disable the alerts (search “emergency alerts” in your phone settings), experts warn this could be a fatal mistake.
“This system is not designed to cause panic, but to ensure people are aware of imminent threats and can act quickly,” a government spokesman explained. “This test is part of building national resilience and saving lives in future crises.”
The last test in April 2023 caught many off-guard despite warnings, with reports of accidents as drivers were startled by the sudden noise. This time, officials promise better preparation – though they still won’t reveal the exact date.
The world on edge: Why now?
The timing is no coincidence. With Russia’s war in Ukraine grinding on, tensions between Israel and Iran threatening to explode, and China flexing its muscles over Taiwan, the world hasn’t been this dangerous since the Cuban Missile Crisis.
Add in cyber attacks that could cripple our power grid, the threat of bioweapons, and the spectre of nuclear conflict, and it’s clear why the government believes the time for complacency is over.
As one senior defence source put it: “We’re not trying to scare people, but we are trying to prepare them. The threats are real, they’re growing, and pretending otherwise would be a dereliction of duty.”
Are YOU ready?
When that siren wails across Britain later this year, it won’t just be testing technology – it’ll be testing us. Are we ready to face threats our grandparents knew all too well? Can we summon that Blitz spirit when the bombs could be digital and the enemy invisible?
The government clearly hopes so. Because in an age where war can arrive not with air raid sirens but through undersea cables and cyber attacks, that 10-second screech might be the only warning we get.
One thing’s certain: when 87 million phones light up with that emergency alert, it’ll be the loudest wake-up call Britain has had since 1939. The question is – will we be ready to answer it?
Image credit: Photo by Lauren Hurley / No 10 Downing Street, taken on 14 January 2025 at 11 Downing Street, London—showing Prime Minister Keir Starmer meeting with Temasek. Licensed under the United Kingdom Open Government Licence v3.0 (Crown copyright)
Image page: View on Wikimedia Commons – “Prime Minister Keir Starmer and the Chancellor meet with Tematek”
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