Of the three things government should tend to – national defense, administration of justice, and some public goods  – national defense should be financed from the general revenue. The general revenue comes from taxes, and when they are not enough, from public debt. But when public debt becomes so much that any hopes of paying it down are futile, either taxes are increased or the expenses causing that debt reduced. The immense expense Britain has is the defense of the colonies. The colonies do not pay enough taxes to cover it. Even if well aware of it being a utopia, Smith suggests to either incorporate the colonies into a full union with Britain, which implies taxation (and representation), or let the colonies go.