Answer:
inevitable
Explanation:
Something that "expires", comes to an end. It is often used with a certain length of time. For example this term is very used for food, when reading a food recipient, it tells the expiration date, once this date is reached, the food can't be eaten, it can be harmful for health. The same happens in this excerpt, the separation from Britain is something that can't be stopped, after some time Britain and the Colonies are going to be divided.
