Should powerful countries solve disagreements through war or diplomacy?

For me I think diplomacy is the best way. War brings fear, deteriorates the economy of a given country.

No, at least there are other better ways of resolving conflicts by coming together as G nations and deliberating on the preceding issues and then resolve it amicably.

Diplomacy. Wars not matter how small affects the world negatively

Diplomacy (in which appeasement is part of) has proven to be inadequate in providing solutions to the warring nature of states, what has proven to be effective is making war unattractive for states by being ready and capable of going to war.. Read more about MAD