The USI of India Strategic Yearbook 2021 continues the writing excellence we have established since we started this publication in 2016. We have gained respected reputation as a compendium of professionally researched and presented strategic issues of relevance to India, of both the current time and previous year. As earlier the book provides comprehensive researched articles on contemporary security studies by knowledgeable Indian strategic thinkers and scholars, both from the military and civil field. The articles deal with security issues covering international and domestic affairs presented in five thematic sections titled 'India's National Security Overview', 'Internal Security Issues', 'External Security: India's Strategic Neighbourhood', 'External Security: Pakistan–China Strategic Challenges' and 'National Security Capacity Building'. The articles deal with the existing paradigm of India's national security. They contribute to security studies in fields of international relations, geopolitics, changes in the character of war, technology, organisational changes and internal security threats and responses. They empower the reader to carry out further research on strategic studies. The Yearbook provides an increased "upstream" focus on defence and security policy practice for all military or civilian practitioners in the field and those researching strategic and security issues.