Problems of critical infrastructures cannot be only solved theoretically, because they are very influenced by characteristics of regions in which they are located (besides each region has different possibilities for problems solution and these have been changing in time because the world has been dynamically varied. The critical infrastructures are complex systems the behaviours of which are dependent on many factors internal or external, which have permanent or random occurrences and under their special combinations they cause emergent phenomena leading to the cascade failures of interconnected infrastructures. With regard to role of knowledge in management and trade-off with risks they also include the infrastructures ensuring the education and the research even though some politics do not respect this reality.