@Pasta: I think he said it depends on how much of your influence your nation is able to impose upon others. If your nation is constantly ending people's wars with diplomacy, it might become more important. Same if.. like, you have a serious hold on resources that make a lot of people dependent on you. And, obviously, if your nation is able to use sheer force to get what it wants, it'll probably be somewhere high in the tier scale.

But I imagine that being active on the world stage would help too. Even if it's just getting involved in international topics.