Archives were searched, journals read and the odd book discovered. For the discerning strategist, the following detail is provided. Note that the UK never committed such plan to paper, but some good guesswork assessed their likely operations.
Pre Conflict Comparison
The Royal Navy had slightly more naval power, with the main battle line spread between the Home Fleet and the Mediterranean. It would be able to rapidly concentrate and venture across the Atlantic to have significant presence at Nova Scotia within 13 days. In comparison, the bulk of the US Navy battlewagons were in the Pacific and the timely use of the Panama Canal was critical in being able to face off against the British fleet in the Atlantic.
Royal Navy US Navy
Battleships 16 18 (12 in the Pacific)
Battlecruisers 4 0
Aircraft Carriers 6 3 (larger capacity than RN equivalents, all in the Pacific)
Cruisers 62 18
Destroyers 175 221
Submarines 57 68
Air Force strength was significantly in favour of the British, though redeploying it to Canada would take significant sea lift capacity. The British could muster such lift capacity but it would have to be balanced with other priorities, such as ground forces.
Fighter Squadrons 12 3 Pursuit, 2 Attack
Observer Squadrons 5 9
Bomber Squadrons 11 2
Manpower wise, the British Army could rapidly mobilise more soldiers from across their dominions than the US, but the US could build a greater land force over time.
Regular Forces 100,000 man Expeditionary Force (4 Divisions, 2 Cavalry Brigades)
Deployable to Nova Scotia within 30 days
Overseas Forces Canada: 52,000 (increasing to 120,000 in 11 Divisions in 30 Days)
India and ANZAC forces: 13 Divisions available at short notice
Territorial Army 13 Divisions available within 6 months
Regular Forces 100,000 men at home,
Overseas Forces 40,000 in Panama, Philippines, Puerto Rico and Hawaii
National Guard 175, 000 (60 days to mobilise)
18 Divisions (understrength), 9 Cavalry Brigades
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