Currently, global security concerns (terrorism, disputes over natural resources, financial instability, organised crime, cyber-threats, etc.) have undergone a great transformation and are considered to be challenges to the security of states and to humanity, and are considered to be of similar importance to traditional military threats to international peace and security. There is growing and legitimate concern in countries and regions characterised by constitutional and democratic political systems (as it is the case in Spain and Europe) about the repercussions that this security transformation, and consequently the means that states are implementing to defend and protect their citizens from new threats, has on the citizens' and non-nationals' fundamental rights in the countries that adopt them.

This is a natural concern, since both security and freedom, the protection of individuals as well as compliance with the legal system and international rights obligations assumed by states, are common goods that must be preserved in a balanced way.

From this perspective, the research team presented here deals specifically with a real problem in our society, namely how states' responses to certain threats (specifically the responses - regulatory and political action - to armed conflict, terrorism, cyber-threats, organised crime and espionage) are affecting the guarantee of citizens' public liberties (specifically privacy, communications confidentiality, personal freedom and other related rights such as freedom from torture, freedom of expression, freedom of association, freedom to demonstrate and procedural laws). This is with the intention of carrying out a series of proposals for approaches, regulations and public policies aimed at contributing to the resolution of the problems that this affectation may entail, both for the protection and security of individuals’ effectiveness as well as for the constitutional guarantee of their rights. Keywords: rights and freedom.