well i personally think saudi arabia can become large togheter with china ofc... they have all that oil and is the richest african country togheter with qatar. If they can use the oppurtunity they got they can become a large nation

Probably China or Japan. They have the best economies. Also India may, according to studies by 2050 India will have economically caught up to the U.S.

Any kind of economic prediction further than 10 years into the future is bullshit. The amount of unknown factors is huge.

i think China will, because they have the latest equipment,(for war) and they have and huge population, and loads of money.

either china or russia they both have good military but china has alot moreadvances in tech. so mostlikly china

O rlly?
Russia.

I find that incredibly low, of actually happening.

China obviusly.
if they decide to be more friendly of course.

I'd say Korea, becuz they have powerful "Fusions" as they call em[But only in warfare]
Doh About the Economy and stuff , ill go with China.

People are overlooking things. China's economy is probably going to crash and burn when the USA fails as a superpower. They're incredibly dependent on each other. Not to mention their population and education problems. I doubt India will become a super power. They have nearly just as big of a population problem as China. They also do not have a good economy. Russia has a good chance, But I do not know much about Russia, so correct me if I'm wrong. My vote goes to Russia because they are not as dependent on the USA like other nations.

Also, how is the USA going to fail? are we talking war, or an economical crash?

The USA is failing as economical superpower now. It was provoked by China, as it invested alot into USA economy. Honestly, I hope no superpower will appear, as we do not want another "peacemaker" country, after what the USA did in various places of the world. Economically, whole world already depends on China, so answer is obvious - economically strongest nation is China, though India is catching up.