The role of the services described in this paper is to support decisions in the Critical Infrastructure Protection (CIP) domain. Those services are perceived as the most fundamental functionalities, that will serve as a basis for the planned European simulation centre for modelling the behaviour of Critical Infrastructures (CI). The proposed services are: CI-related data accessing and gathering, threat forecasting and visualisation, consequence analysis, crowd management, as well as resources and capability management. In general, services proposed in the current paper will contribute to reducing the problem of overwhelming decision makers by too large amount of information. In the crisis, their decisions are made on the basis of the large amount of data related to the current situation, such as the status of CI, localisation of capabilities, weather and threat forecasts etc. The design of the services has been established with the help of the future end-users. The work presented in this paper is the result of preliminary activities performed in the FP7 project CIPRNet.