Air strikes on Iran by the US military are reported to have been called off with just minutes to spare this week, amid rapidly escalating tensions between the two powers.
The New York Times says that US warplanes were in the air ready to launch strikes, and ships in position for a bombardment, when the order came from the President Donald Trump to cancel the attack. The showdown on Thursday evening came in response to the shooting down of a US military surveillance drone that Tehran says had violated Iranian airspace - a claim the US has denied.
According to Reuters, Iranian officials had received a message from the US president via Oman warning that an attack was imminent and saying he wanted to discuss the situation with them urgently.
One official said: “In his message, Trump said he was against any war with Iran and wanted to talk to Tehran about various issues... He gave a short period of time to get our response.” Iran later denied that the Reuters report was true.
The targets in the shelved US attack were said to be military, and the missiles would not have been nuclear – but Iran's nuclear capabilities remain a source of international unease, and one of the sticking points in the country's cold war with the US.
An intercontinental ballistic missile (ICBM) with nuclear warheads fired from Moscow or central Asia would probably take about 20 minutes to strike London, The Daily Telegraph says.
US-style sirens are unlikely to be used as a warning if an attack occurs, however. The “four-minute warning” air raid signals operated during the Cold War were almost entirely dismantled by the 1990s, so it is more likely that TV and radio would instantly switch to the news.
While a text message warning is a likely option, the UK doesn’t appear to have a system in place specifically for the purpose of a nuclear attack. According to a BBC report: “A spokesman for EE told the BBC News website the UK government was ‘working with the mobile industry to put this capability in place’.”
The Cabinet Office’s Civil Contingencies Secretariat, responsible for emergency planning in the UK, told the broadcaster that emergency management arrangements were “robust... and include the capability to warn and inform the public through a range of channels including social and broadcast media platforms and direct alert such as the flood warning system”.
In 2016, the BBC revealed the contents of the so-called War Book, which was drawn up during the Cold War and contained detailed plans for broadcasting in the event of a nuclear strike, but current broadcasting arrangements are not public knowledge.
On the military front, an attack could see the UK’s new aircraft carrier HMS Queen Elizabeth, along with 12 F-35B fighter jets, brought into service to join US warships off the Korean Peninsula, say the Daily Mail. The carrier and 700-strong crew could be escorted by Type 45 destroyers and Type 23 frigates, the newspaper adds.
The US Department of Homeland Security’s ready.gov website says that home or office basements offer more protection than those on the ground floor, and recommends shielding behind dense materials such as thick walls, concrete, bricks, books and earth. Radioactive fallout poses the greatest threat to people during the first two weeks, by the end of which it has declined to about 1% of its initial radiation level, the website says.
While the UK considers the likelihood of a large-scale chemical, biological, radiological or nuclear attack “highly unlikely”, it cannot be ruled out, according to the 2017 UK National Risk Register Of Civil Emergencies.
“The matter-of-fact advice included everything from stocking up on loo roll and packing a tin opener to remembering to pack a warm coat and toys to entertain the kids while holed up in a bunker,” says the Daily Mirror.