No, we're not criminals. It's OK under international law (see
Uphold International Law | United Nations ).
If the USA broke an international law, then that'll be criminal. Until then, it's just your opinion.
Yes, its totally fine for the strong and powerful to take advantage and exploit the weak for their own benefit.
It's been happening since the beginning of mankind.
You probably enjoy many benefits from it too.
For example, look at slavery. Back then, society needed laborers and slaves were a good way of getting stuff done. Today's society got here thanks to slave labor powering the way.
So, yeah, inequality is just an inherent human condition. If you think otherwise, someone's taking advantage of you or manipulating you.