Preparation for WW3 worst-case scenarios could be stepped up after the head of the army called on the UK’s political leaders to start a ‘frank conversation’ with the public about preparing for war.

General Sir Roly Walker told Sky News that ‘every’ citizen will be ‘asked to make sacrifices’ and play their part in the defence of the country.

It comes in the wake of escalation between Russia and Ukraine as the US, unthinkably, appears to be siding with Russia. US President Trump has in the past week urged Ukraine to ‘get a new leader’ after signing a deal with Russia for diesel supplies, and has increasingly blamed the global price of diesel on Ukraine’s refusal to surrender to Putin, rather than the US’ war with Iran.

It’s not something anyone wants to think about, but as tensions escalate around the world, there is a possibility that World War 3 could erupt. Just this past summer, the UK government last year told people to prepare for war on British soil, and is urging better preparedness for conflict across society.

Assuming tensions continue to ramp up and a new global conflict were to erupt, there are some indicators about what would happen if the UK went to war and needed to introduce conscription, or mandatory military service, whether in a WW3 situation or not.

In WW2, conscription began for men aged between 20 and 22 in 1939, up to six months before the war actually broke out.

The UK Parliament website says: “During the spring of 1939, the deteriorating international situation forced the British government under Neville Chamberlain to consider preparations for a possible war against Nazi Germany. Plans for limited conscription applying to single men aged between 20 and 22 were given parliamentary approval in the Military Training Act in May 1939. This required men to undertake six months’ military training, and some 240,000 registered for service.”

But when war was declared, the age range was immediately widened to any man aged 18 to 41.

It continues: “On the day Britain declared war on Germany, 3 September 1939, Parliament immediately passed a more wide-reaching measure. The National Service (Armed Forces) Act imposed conscription on all males aged between 18 and 41 who had to register for service.”

The only men who weren’t called up were those who were too unfit medically, or who worked in vital industries like baking, farming, and medicine, which were vital to the war effort.

It adds: “Those medically unfit were exempted, as were others in key industries and jobs such as baking, farming, medicine, and engineering.”

By the end of 1941, women and ‘all childless widows’ between the ages of 20 and 30 were called up, while men aged up to 51 were called up for military service. Even those aged 52 to 60 were required to take part in “some form of military service.”

In 2024, Grant Shapps, who at the time was Defence Secretary, said that we are “moving from a post-war to a pre-war world”, and General Sir Patrick Sanders, Britain’s most senior army officer, called for an increase in the size of the army and said that the country needed to increase preparedness for conflict.

It isn’t clear what would happen to those refusing to serve in a potential WW3 scenario, but in WW2, British ‘conscientious objectors’ were put on trial, with some given mandatory jobs to contribute to the war effort in other ways instead.