Conscription is the compulsory enlistment or "call up" of citizens for military service. The federal government enacted forms of conscription in both world wars, creating sharp divisions between anglophones, who tended to support the practice, and francophones, who generally did not.

First World War

In the South African War of 1899–1902, several thousand Canadians had volunteered to fight for the British Empire overseas. Conscription for Canada's limited war effort in Africa had therefore not been necessary. The same was true during the early years of the First World War, when huge numbers of Canadian volunteers — 330,000 overall from 1914–1915 — willingly went to fight against the Germans in France and Flanders (Belgium).

By late 1916, however, the relentless human toll of the war and the terrible casualties at the front in Europe were beginning to cause reinforcement problems for the Canadian commanders overseas. Recruitment at home was slowing, and the manpower and enlistment system was disorganized.

For Prime Minister Sir Robert Borden, the first necessity was to assist the men in the trenches. In May 1917, when he returned to Canada from the Imperial War Conference in London and from visits to the trenches, he had decided that compulsory service was necessary. He announced his decision in Parliament on 18 May and then offered a political coalition to Liberal leader Sir Wilfrid Laurier. After consulting his supporters, Laurier refused. Québec would never agree to conscription, he believed, and if he joined the pro-conscription coalition, French Canada would be delivered to the hands of such Québec nationalists as Henri Bourassa. The course was set for collision.

By the fall, after enormous difficulty, Borden had created his Union Government, and the Military Service Act became law on 29 August 1917. Virtually every French-speaking Member of Parliament opposed conscription, and almost all the English-speaking MPs supported it. The eight English-speaking provinces also endorsed Borden's move, while the province of Québec opposed it.

The federal election of 1917 was similarly divided. While neither French nor English Canadians were unanimous in their views on the subject, English Canada, broadly speaking, gave Borden his mandate to put conscription into effect. The process of call-ups began in January 1918. But out of the 401,882 men registered for conscription — and though certain exemptions from call-up were lifted in the spring of 1918 — only 124,588 men were added to the strength of the Canadian Expeditionary Force; only 24,132 of those made it to France by the war's end.

As a military measure, conscription was a failure; as a political measure, it was largely responsible for the re-election of the Borden government, though it left the Conservative Party with a heavy liability — and feelings of betrayal — in Québec and in the agricultural West.

Second World War

Two decades later, as the threat of a new war in Europe became acute, the question of military conscription again caused lively political debate in French Canada. The federal Liberals, sensitive to strong francophone feelings on this issue, repeatedly pledged not to resort to compulsory enlistment for overseas military service.

War broke out in September 1939, and by the spring of 1940 the government had adopted the National Resources Mobilization Act providing for enlistment only for home defence. Registration took place almost without incident, except for the public opposition of Montréal mayor Camillien Houde, who was later interned after he urged constituents to ignore their call-up papers.

In 1941, as recruitment slowly progressed, more voices were raised in favour of conscription, first within the Conservative Party and later among English Canadians in general. To appease supporters of conscription, Prime Minister Mackenzie King decided to hold a plebiscite asking Canadians to release the government from its anti-conscription promises.

In Québec, the Ligue pour la défense du Canada campaigned for the "no" side. On 27 April 1942, 72.9 per cent of Québec residents voted "no," while in the other provinces the "yes" vote triumphed by 80 per cent. The government then passed Bill 80, authorizing conscription for overseas service if it was deemed necessary. Québec's Bloc Populaire continued to fight against conscription by presenting candidates for the August 1944 provincial elections and the June 1945 federal elections.

By the autumn of 1944, J.L. Ralston, minister of national defence, was convinced of the need for overseas conscription. Unexpectedly high casualties on the front, combined with a large commitment of manpower to the Royal Canadian Air Force and Royal Canadian Navy, left the Canadian Army short of recruits. King, who had hoped he would not have to invoke Bill 80, replaced Ralston with General A.G.L. McNaughton, who did not support conscription. On 22 November, however, the prime minister — acknowledging the open pro-conscriptionist sentiments of many of his anglophone ministers — reversed his decision in an effort to save his government, and announced that conscripts would be sent overseas.

Only 12,908 conscripted soldiers, disparagingly known as "zombies," were actually sent abroad — a tiny number compared with the hundreds of thousands of Canadian volunteers, including French Canadians, who fought overseas. Still, this second conscription crisis worsened relations between anglophones and francophones in Canada, though to a lesser extent than during the First World War.