I dunno, 12 million people live in South Sudan, and irrespective of that, there is not a single thing that every country agrees on. Even the definition of what a country is.

How would you define a country?

There’s also plenty of “global” treaties that United States is not a party of. Does this make the US a “irrelevant country”?

South Sudan is barely a state, as we both know, and is still fairly recent. Give them a few years.

The US doesn't accede to these treaties because it has a huge economy and military.