system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are the four parts of the UK defined as countries, but the fifty parts of the US are states within one country? What makes the two different when it comes to unified governing?

I’ve always found it difficult to understand what the difference was between the US and its states (or Canada and its provinces) and the UK and its kingdoms. England, Wales, Scotland, and Northern Ireland are all defined as countries, but make up parts of a larger entity, whereas the US is one country. Do the countries self-govern in worldwide matters, such as war, trade, diplomacy, etc. or do they have to come to a decision as a group? What are some of the major political/government differences between states/provinces in the US/Canada and the countries that make up the United Kingdom?
gpt
In theory, US states and Canadian provinces are more independent than UK countries. This is because the US and Canada are federal states (power is shared between central and state/provincial governments) while the UK is a unitary state (all power is vested in the central government).

For example, the UK government dissolved the Northern Ireland government during the Troubles and ruled directly from London, which is legal under their system of government. Meanwhile, in the US, there is no legal way for the federal government to dissolve a state government. Not sure about Canada, but it’s probably the same.

In *practice*, however, the Home Countries of the UK (except for England) have a lot of power devolved to them by Parliament and they function much like American states or Canadian provinces. They’re called “countries” for historical reasons, it has nothing to do with how independent they are.