Canada's weight in the Battle of the Atlantic

How much harder would the Second World War have been for Britain if Canada had remained neutral?

Canadian neutrality would create a major convoy-escort gap and force Britain and the United States to shift resources into the Atlantic.

Canadian neutrality would remove a large contribution of escort ships and aircrews from the Battle of the Atlantic. Canada's concentration on this theatre made its contribution especially important even alongside the larger British and American forces. The United States supplied ships and other resources on a vast scale, but its commitments across several theatres limited what it could concentrate in the Atlantic. At some points, the available American contribution included more Coast Guard ships than US Navy ships. Britain and the United States would have to divert substantially more resources into the Atlantic to replace Canada's sustained effort.