Hey, Fred the Bat, mind your spelling in the sentence below. "Its" would be the correct way to write it here as it refers back to "USSR" and is a possessive pronoun. "It's" on the other hand is a contraction from "it is" and would not make sense here. I am afraid you need to polish up your English a bit before you should be allowed to really teach it.

But thank you for providing the opportunity to comment on it. It proves that I am right in two points I have made before:
1. It's not enough to merely be a native speaker to qualify for teaching in ESL. You need thorough formal training as well, and if you don't have it, you are useless.
2. You will need a degree to qualify for teaching. Only with 3 - 4 years of full-time rigorous academic uni/college training with at least a Bachelor degree at at the end, you will have enough education to know why you should write "its" instead of "it's" in cases such as this.

Some non-native speakers of English are obviously better at English than you are as a native speaker......hahahahahahaha

I wonder how our Fred will answer that attack on his 'it's;' as you quite rightly point out ,incorrect? If he had been writing a paper for his publisher on say 'primitive man and his dough' He could have dismissed it saying "Been having trouble with my eyes lately and what with the pressure of publishing deadlines I did a TYPO, so I did. However, I think we should allow Fred that one as a typo- what do you say?

Listen Turnoi, please. Native born English speakers have been in rigorous training since they were two months old. All some-body like Fred would need before commencing his first class as a qualified teacher would be a week's training on the job. He would be worth ten second language English teachers; who should not be allowed to teach anyway. Apart from their own languages that is.