The United Nations and the necessity of global governance
This is a well defined topic and clear indiciation of your position/opinion in the title. You might find it useful to also link this issue to Global Regulation, Global Business Ethics, and Global Common Good  in the theme Economic Dimension of Globalisation.
I came across an article which might interest you, Jan. It is pubished by the United Nations Chronicle online, co-authored by the ex-rector and vice-rector of the UN University. It is called A Safer World and a Better Life for All, accessible here: http://findarticles.com/p/articles/mi_m1309/is_/ai_66579826 Laura Macháčková Henderson
Comments on thesis and research question
Well done for taking the bold step to tackle a big theme and express your ideals. Your point about your conviction in the need for more power for the UN is clear. The second part of your thesis statement suggests that a shift in values ("respectful and responsible") is necessary. You hint at how you think the UN system should play a role in changing values in order to manage the "economical, social and environmental challenges" you mention. Perhaps you could acknowledge the relationship between values and institutions - institutions are shaped by laws which in turn are an expression of norms which are again in turn based on our values. I suggest you make your position on values more explicit in your thesis statement.
Laura Macháčková Henderson
My Comments on thesis and research question
- Question OK - although "acting" is vague term, do you mean control, governance, NGOs?
- Thesis - you have written rather arguments supporting your hidden thesis. Feel free to express it! E.g. "There is a need to change global thinking (values) which should be reflected by changed institutional system - the process has started." Then, question is Why? and What for? and How?
The article is built round clear idea.
Imperfections: the idea and possible solution of the problem are not supported by evidence. Sentences that include: " in my mind," or "As we all know" are inaceptable in the article that is ambitious to be scientific. As the theme is too broad, it inevitably leads to a pesimistic conclusion. Any international institution could be changed by small steps based on evidence, negotiations, analysis etc. - and of course good will. Radical, revolutionary changes may be a consequence of a disaster, but this vision should not perhaps be part of solutions offered by analytical view. Tjis is more journalist style of argumentation. Author has to be much more concrete in the future - either say which part etc. of UN should be reorganized and how, or write about the basic principles on which the change should be built, and their difference with current principles (select one or two examples).
I think the author clearly presented his idea of a reformation of the UN and gave his essay a good structure with first explaining why a reformation has to be done followed by the demonstration of structural deficits and in general undermining of the UN role by certain states. Then he formulates concrete ideas for a reformation but without missing to mention also the obstacles. To my mind, the author of the essay is very reflective and realistic when formulating concrete ideas like "it is necessary to have an exact and explicit constitution with powerful control mechanisms". The author always refers to current and historical incidences which makes his thesis very comprehensible and descriptive. I liked reading the essay because the author accomplishs to explain such a complex issue in a clear way that even readers without a lot of previous knowledge might understand the difficulty.
The author did not follow the citation rules and there are a number of grammatical failures which could have been avoided.