Creating a diagram or outline allows you to put pen to paper and start organizing your ideas.
Don't worry or agonize over organization at this point, just create a moderately organized format for your information.
It introduces the reader to the idea that the essay will address.
It is also intended to capture the reader's attention and interest.
However, if you're expected to write a specific analysis, then you're topic should be fairly specific.
For example, lets assume the objective of your essay is to write an overview. However, if the objective or your essay is to write a specific analysis, then "RUSSIA" would be far too general a topic.
When selecting a topic for your essay, you'll want to make sure your topic supports the type of paper you're expected to write.
If you're expected to produce a paper that is a general overview, then a general topic will suffice.
The word "thesis" just sounds intimidating to most students, but a thesis is actually quite simple.
A thesis statement (1) tells the reader what the essay is about and (2) what points you'll be making.