The threat of foreign terrorist fighters has led to the development of preventive criminal law on an international and European level. The EU Directive on combating terrorism can have two impacts on the free movement of EU citizens. It directly calls upon
Member States to criminalise the act of travelling, as well as other conduct that may be connected to a terrorist offence. In addition, ecj case law accepts EU criminal law as a basis for public security derogations against free movement. Therefore, the commission of any of the acts criminalised in the EU Directive on combating terrorism could be used as a reason to restrict the exercise of free movement by EU citizens. When Member States begin to adopt these measures, litigation on the balance between preventive criminal justice and free movement of EU citizens will increase.
