While fighting to retain, or perhaps regain, their colonies in North America, the British had to spread their naval and military strength widely and sometimes very thinly. The army, never a large force even when supple¬mented by hired soldiers from Germany and by new recruits, had little chance of both reconquering and then holding much of the North American colonies, which were in general thinly populated, and were twice the area of the British Isles. It could certainly capture and hold the urban centres such as New York and Philadelphia, but it had little hope of controlling the countryside. And when it became necessary to fight in India, in the West Indies, at Gibraltar and on Minorca, and to garrison Ireland, which was turbulent, it turned out that those American colonies were one of the British government's lesser considerations. As a result the army in North America was stuck in the few places it controlled, and was able to do no more. Cornwallis’ southern campaign could beat every enemy army (except the last one, which was heavily reinforced and equipped by the professional French army), but it could not occupy territory – and the battles it fought were puny by comparison with those in other theatres.

Once the realisation of the impossibility of success by land finally dawned, however, the navy no longer came under the same sort of pressure. In 1781, for the second time, a great Combined Fleet of French and Spanish ships had reached the western English Channel, threatening an invasion of England, but had then broken up because of command disputes, disease, shortage of supplies, irresolution, and ignorance of the whereabouts of the British fleet. This failure in effect put paid to any repetition of such a venture, at least in that year and perhaps for longer. This was realised in Britain, and so it became possible to concentrate British naval strength where it would be most effective. This was also the reasoning of the French and Spanish navies.

In the aftermath of the news of defeat in America there came news of a major French expedition being organised in Brest. Its size varied with rumours and news, but it was evidently destined for the West Indies, and attention was suddenly focused on Jamaica.