Many people confuse politics with diplomacy (and vice versa), despite the very huge difference between the two. They don’t get why countries have a foreign minister and a diplomate at the same time. They also don’t know when to say “a great politician” or “a great diplomate” about someone.
Politics and diplomacy both include negotiation. But there are differences between this two concepts which are: the entities involved and the nature of action.
We talk about politics when it is about a country. The entities work only on what concerns that one area. Those entities are all the influencers who are involved on the country’s affairs. They may be ministers, members of parties, law-making organizations … And all of them collaborate on governance.
Meanwhile, diplomacy is simply the relationship’s management between countries. The entities here are the countries obviously, and the action is how to find a middle ground despite the different intern governance of each.
Countries need diplomacy because they have different politics.
With the same logic and on a larger perspective, politics and diplomacy can be skills: the first will be the skill of management and guidance and the second the skill of dealing without upsetting.