This book deeply analyzes the situation of cybersecurity in current international relations; The cybersecurity policy of major powers and nations near Vietnam. On that basis, the authors make some recommendations on cyber security policy from foreign relations perspective. The book consists of 3 chapters. Chapter 1: Cyber security and current situation. This chapter analyzes the basic aspects of cybersecurity; cybersecurity issues during the 4th industrial revolution; challenges and risks for cybersecurity; cooperation and struggle among the powers in current international relations on cybersecurity. Chapter 2: Policies on cybersecurity and the situation of cybersecurity cooperation of some countries in the world including: United States, Russia, China, EU, Southeast Asia. Chapter 3: Policy recommendations on cybersecurity for Vietnam. This chapter analyzes the reality of Vietnam cybersecurity, focusing on legal and policy factors; achievements and limitations in ensuring cybersecurity.