(For previous posts in this series, see here.)
While the colonies were a prime source of revenue for England, they also served as places to send young English men who were seen as black sheep in their well-connected families or as places where the less well-connected could make their fortunes. But the British could never hope, by sheer force of numbers and soldiers, to keep their far-flung empire under their control for a long time. Even the strong and well-organized Roman empire collapsed under this kind of logistical strain, and we see the same thing happening right now with the US trying to maintain its global dominance militarily. It is causing immense stress on its budgets and threatening to bankrupt the country.