@FieldMarshalGames:
I don’t think that is the case. Why don’t you hear it from Winston Churchill himself. Read his Pulitzer Prize winning History on the Conflict The Second World War, Vol 2 ALONE. Then you will discover just how un-prepared and at the mercy of the enemy Great Britain was. Second to the Military support received by the UK in the Early war from Canada was the Moral support that England was not Alone… Winston Churchill would not have been called to form a Government after the fall of Neville Chamberlain, but rather Lord Halifax, who was committed to a peace settlement with Germany in the face of what seemed impossible odds for victory and utter defeat and destruction.
In this fragile period after the Fall of France and the evacuation from Normandy, with Luftwaffe attacks nightly on British cities… Great Britain was near the point of collapse and most of the powers that be agreed a negotiated peace settlement was the only way out. It was the Solidarity of the Commonwealth and Empire (thus the declaration of support from Canada also) that gave the United Kingdom any slight hope of final victory or even holding out.
In conclusion; Being the largest British Dominion and closest to Great Britain, Had Canada not declared war on Germany in 1939 and began logistical and military support for the United Kingdom… the British ability and will to stay the course and continue the conflict is in doubt. Regardless if it was from actual Military defeat and invasion, or the internal victory of the Defeatist block who wanted to end the war and negotiate with Hitlers Germany.
Suppose Canada had refused to declare war on Germany, and suppose that had led to Halifax, not Churchill, becoming the British prime minister. Britain would have negotiated a peace treaty with Germany.
What would have happened then? Would Hitler still have invaded the Soviet Union? Would that invasion have occurred in 1941, or would he have waited? Or, conversely, would the Soviet Union have invaded Germany?
If a war between Germany and the Soviet Union did occur, how much American aid would the Soviets have received? There can be no doubt which side FDR personally would have favored in such a war. But if the Soviet Union was the only nation with which Germany was at war, would he have been able to sell the American public on what would have boiled down to military aid to protect and spread communism? (As opposed to spreading Western democracy and communism, as the historical Lend-Lease program achieved.) Without British naval involvement, how able would Germany have been to sink those Lend-Lease shipments as they crossed the Atlantic on their way to the Soviets? Would those attacks let FDR get away with bringing the U.S. into the war?
If no war between Germany and the Soviet Union occurred, and if the British had agreed to peace, the Cold War era would have had three sides: the Western democracies, the communists, and the Nazis. Most or all of the illegal killing within Germany would likely have ended once the British food blockade had been lifted. Hitler would eventually have died, and would likely have been replaced with a milder man. (Just as Stalin’s successors were more cautious and less murderous than Stalin himself.) The massive wave of Third World immigration into Western and Central Europe which began in the post-WWII era, and which continues today, would not have occurred. The Red Army would have been kept out of the heart of Europe, thereby preventing countless atrocities. Eugenics had been socially acceptable prior to WWII, and would likely have remained so during this postwar era. Even in Western democracies, programs might have been put in place to encourage more intelligent people to have more children, and less intelligent people to reduce their reproduction. (Such programs were favored by John Keynes, the most influential economist of the 20th century, and Leland Stanford, founder of Stanford University.) Communists’ influence in the postwar era might have been weakened, and there is at least the chance that the social revolution of the '60s might not have occurred. (Or might have been milder and more moderate if it did occur.)