Britain's regular army had a second great-power role beyond supporting allies in Flanders: it could turn sea control into pressure ashore. The Copenhagen attack of 1807 and Walcheren expedition of 1809 showed how troops could help destroy hostile fleets and naval bases, an approach repeated in the Crimean War. Once the allied army was no longer needed defensively in Bulgaria, it was sent to Sevastopol to reinforce economic warfare against Russia. Reserves at home replaced regular units and supplied trained replacements for expeditionary losses. Wellington and later advocates used invasion fears because this outward-looking maritime purpose was harder to sell publicly, even though a French invasion was not considered credible.
Chapter · 33:44-35:30
The army as an instrument of maritime strategy
Britain used expeditionary troops to exploit sea control, strike hostile naval bases, and sustain economic warfare while reserves covered duties at home.