After the British islands themselves, the North American colonies were the most valuable possessions in the eyes of the England of that day.

Next should have been decided what others by their natural importance were best worth preserving, and by their own inherent strength, or that of the empire, which was mainly naval strength, could most surely be held.

In the Mediterranean, for instance, Gibraltar and Mahon were both very valuable positions.

Could both be held?
Which was more easily to be reached and supported by the fleet?
If both could not probably be held, one should have been frankly abandoned, and the force and efforts necessary to its defence carried elsewhere.

So in the West Indies the evident strategic advantages of Barbadoes and Sta.
Lucia prescribed the abandonment of the other small islands by garrisons as soon as the fleet was fairly outnumbered, if not before.
The case of so large an island as Jamaica must be studied separately, as well as with reference to the general question.