Dakar’s position put Atlantic convoys, including the sea route around Africa to Egypt and the eastern Empire, within easier reach of French warships and submarines. Their presence at the base raised the fear that German submarines might follow. Operation Sea Lion’s practical viability is treated skeptically when compared with the effort later required for Operations Overlord and Torch, although the invasion threat still had to be taken seriously. German leaders might still attempt an invasion if they believed they had a chance. Britain also needed operations that demonstrated resolve, supported the North African campaign, and showed that it could eventually return to occupied Europe.
Chapter · 16:27-18:47
Britain’s September 1940 strategic aims
Britain needed to keep Atlantic routes open, deter invasion, sustain the North African war, and demonstrate that it could still take the offensive.