In a legal comparison between America, England and New Zealand this book demonstrates the Judiciary´s struggle to retain its constitutional role as guardians of the rule of law in times of war and crisis, while not curtailing the necessary latitude of the Executive when dealing with matters of national security. It carves out the reasons for Judiciary´s hestitation regarding more drastic judgments and defines the required collaboration between the branches of each constitution for a necessary approach of the matter. America, as it was the first target of the new era of terror and its constitutionally strong Judiciary. England as part of the United Kingdom, its parliamentary constitutional concept and the influence of the accedence in a Union of civil law countries. Finally New Zealand, arguably one of the countries of the modern world with the weakest form of judicial review. The book provides a review of selected jurisdiction enacted during the World Wars and the current “War” against terror, based on executive measures such as indefinite detention without trial, restriction of movement or deportation of undesirable foreign nationals, violating human rights at its core.