(b) Although, owing to variable factors such as future rate of shipping losses and possible shipping replacements, it is at present impossible to estimate the earliest date at which the enemy might be starved out or forced to withdraw through lack of supplies, it is safe to assume that the island garrisons can and will be maintained for at least another four months, and probably for longer. 4. The Estimate is being passed to the Admiralty for retention. (Signed) E.J. KING-SALTER. Offices of the War Cabinet, S.W.1.