Assess the legitimacy and proportionality of executive emergency and counterterrorism powers enacted after 9/11 in the United States, United Kingdom, Germany, and France. Evaluate relevant constitutional provisions, statutes, and key case law; apply doctrinal standards (necessity, proportionality, margin of appreciation/constitutional identity) and analyze the effectiveness of judicial and legislative oversight in constraining abuse while addressing security needs, drawing comparative conclusions supported by legal texts and empirical outcomes.