We are one of five permanent members of the Security Council as spelled out by this document. You asked.
Learn to read and comprehend.........the UN charter is NOT one of our foundational documents. Reference the Declaration of Independence and the U.S. Constitution.
Declaration of Independence has no legal bearing
Neither does the UN charter. Just an agreement between nations.
And quit avoiding the question, where does it state that the U.S. has the responsibility to be the world leader?
In the Constitution.....Article II
The President receives all foreign Ambassadors. This clause of the Constitution, known as the Reception Clause, has been interpreted to imply that the President can be granted broad power over all matters of foreign policy by Congress,[24] and to provide support for the President's exclusive authority to grant recognition to a foreign sovereign
So the president can "recognize" a foreign sovereignty, I'm betting the heads of state of the other 190+ countries of the world have a similar authority. Does it make them the leader of (insert power wielding title here) of the world?
I agree and I'm sure those other 109+ countries aren't fighting each other to be seen as "leader of the free world."
I vote the Brits as leaders of the free world.