The strategic value of containing Japan is economic as well as operational. If Japanese forces cannot reach the Atlantic, Indian Ocean, or Mediterranean routes, British trade can continue near peacetime levels while the state mobilizes for war. Britain therefore avoids the simultaneous losses and diversions associated with fighting Germany and Italy. Early American participation also spreads the cost and force burden from the beginning. This combination would let Britain sustain the campaign for as long as the blockade required.
Notable Point · 2:24:06-2:24:52
Open trade gives Britain financial endurance
Protecting Atlantic and Indian Ocean commerce lets Britain mobilize for war without suffering the trade shock imposed by Germany and Italy.