The book passage presents destroyers as fast, manoeuvrable ships with valuable anti-aircraft firepower, even though they were poor substitutes for proper troop transports. Bertram Ramsay's evacuation plan therefore depended on vessels that were already among the Royal Navy's most heavily demanded assets. Diverting them from the Home Fleet and Atlantic work was a serious risk while Britain depended on ocean shipping and purpose-built corvettes had not yet arrived in strength. German naval losses during the Norwegian campaign reduced the immediate danger of a surface sortie into the Atlantic. British planners did not yet know how much those losses had lowered the price of concentrating destroyers at Dunkirk.
Notable Point · 10:27-11:17
Why committing destroyers to Dunkirk was a strategic risk
Destroyers could ferry troops and defend the evacuation, but drawing them from fleet and convoy duties exposed wider Royal Navy priorities in 1940.