Correct. From an economic perspective, productivity is the root cause of this disparity. The more productive the country is, the richer they are. And this productivity is impacted by their natural resources available, educational and healthcare system, infrastructure, availability of finance, etc. On a micro perspective however, countries behave like we do --We compete for dominance, some outsmart the others with better deals, while some will rob the other just to get ahead. This is the same reason why our environmental resources are depleting.
We've gotten so used to this gap between the rich and the poor, that it's impossible to even imagine equality or working successfully to solve world issues.