The resurgence of great power competition has intensified Chinese and Russian espionage activities in Europe, posing significant threats to security and stability. China seeks technological dominance through legal and covert means, while Russia, driven by its confrontation with the West and the war in Ukraine, engages in aggressive intelligence operations to bypass sanctions and destabilize societies. Both actors employ a blend of traditional human intelligence (HUMINT), sophisticated cyber operations, economic coercion, and influence campaigns targeting critical infrastructure and democratic institutions. This report analyses their goals, methods, and recent cases of political, military, technological, and cyber espionage, compares their strategies, and explores implications for European security, offering recommendations to strengthen resilience against these growing threats.