If Germany declined to build a challenging navy or submarine force and explicitly left Britain secure at sea, London might hesitate to enter a purely continental war on France's behalf. Formal ties would not erase British frustration with the repeated changes and policy reversals of French governments. That distrust helps explain the British calculation at Mers-el-Kebir in 1940: ministers feared that the government making a promise might not remain in office to honor it. This explains their reasoning without justifying the attack, and the concern was governmental reliability rather than hostility to the French people. Staying out of a continental war could still leave Britain facing a humbled France and a Europe dominated by Germany and Italy. That danger could eventually require British and probably American intervention.
Notable Point · 1:29:27-1:32:13
Could Germany keep Britain out of a continental war?
Avoiding a naval challenge might keep Britain out of an initial continental war, but German and Italian dominance after a French defeat could force later intervention.