When choosing a topic, avoid merely describing a significant event or person. The goal is to craft an essay that is analytical and critically evaluates the issue in question. Use the key concepts of causation, consequence, change, continuity, significance, perspectives to frame your analysis.
Instead of asking "What", or "How," ask:
Anything within the last 10 years is considered "current affairs" and is not acceptable. Be sure to choose a topic that is outside of the 10-year range.
You are permitted to choose the same time period or a similar topic for your EE as you did for your IA. However, you must use different sources or, in the case that you use a few of the same sources, you must use additional, different sources.
The following is a comparison of History EE topics to demonstrate the focus and specificity your topic should have.
(Taken from "History Subject-specific guidance" by the IB)