However, political, economic, social and cultural reasons are pretty much the only possible reasons why communism could collapse. Second, the phrase negative and positive aspects is vague. Now that you know where the paper is leading, you will probably need to rewrite the introduction. You have two choices about how you approach this: You find a native English speaker, perhaps a fellow student, who is prepared to read your thesis for you and help you improve the English preferably for free, or at least for the price of not much more than a meal and a few drinks ; or You pay an editor to do the work for you.
It also may spark a defensive reaction from readers sympathetic to communism. Writing this section requires extreme discipline.
You should provide a thesis early in your essay -- in the introduction, or in longer essays in the second paragraph -- in order to establish your position and give your reader a sense of direction. Interpret results in terms of background laid out in the introduction - what is the relationship of the present results to the original question?
Do not repeat the abstract. What are the relationships, trends and generalizations among the results?