The world uses the United States Dollar as the gold standard for currency and stability.
The world does business with the United States.
The world studies in the United States.
Look, I'm not saying the United States has done a good job with foreign policy. What I am saying, is that the world has a lot of trust in the United States to
1) keep its word
2) not pull shady shit
3) continue to be a successful economic powerhouse
4) continue to be stable because of citizen rights / civil rights / free speech / (the foundation is pretty solid seeming)
The proof is in the pudding. USA is #1 economically, trade-wise, and military wise because the world has faith in our institutions, we have relatively low corruption, and fairly strong democracy which peacefully changes hands every 4 years. Am I blindly proud of our country? No - there's tons of room for improvement. Corruption is starting to really throttle our systems... But I look at where the Republican Party is taking us (they're trying to turn us into a Russia), and I start to get really fucking upset. A country run for the benefit of a few rich dudes is pathetic.
If the Russian Oligarchs (And Putin) put the interests of Russia ahead of their own interests, it would be a fantastic country. Unfortunately, they do not. I do not assume they are incompetent. I believe they know exactly what they are doing, and that is they are enriching themselves at the expense of the country. The results are undeniable. Russia should be a superpower, but greed is holding you back.