Jean-Francois de La Clue's defeat at Lagos did not directly alter the invasion plan because his ships were not expected to join Conflans. The possibility that the British Channel Fleet might be reinforced made an already weak plan even less promising. French ships sheltering at Cadiz under de Castellion remained behind Broderick's blockade until January 1760, when they finally returned to Toulon. In hindsight, cancellation made military sense, but France also had to protect its credit and preserve the hope of drawing British power away from America and India. Even an unsuccessful or incomplete invasion attempt might relieve pressure on the French and Canadian army around Montreal. Finance, national standing, and strategy for the wider war kept the operation alive after its military case had weakened.
Notable Point · 5:03-6:55
Why an unsound invasion plan continued
The proposed French landing operation remained politically and financially necessary even though the odds of its success had become poor.