India's atomic energy program has propelled the country towards being a nuclear weapon state and a commercial success in pressurised heavy water reactors (PHWRs). With 19 operational PHWRs and more under construction, India is also advancing towards commissioning a fast breeder reactor using thorium as part of its three-stage strategy for long-term energy security. The vast thorium reserves in India are crucial for producing clean hydrogen and meeting industry needs. The article emphasizes the advantages of thorium utilization in PHWRs, such as safety, improved reactor parameters, and reduced spent fuel arising. This positions India to potentially lead in nuclear energy deployment, particularly in emerging economies where the demand for clean energy is high. India's energy goals align with becoming a developed nation and achieving a high human development index. To meet these requirements, thorium's role in addressing the energy gap, beyond renewable energy potential, is crucial. Leveraging thorium not only supports domestic energy needs and export ambitions but also aligns with the planned three-stage nuclear program. The article stresses the importance of international civil nuclear cooperation, especially with the United States, to support India's thorium-based energy strategy. Collaborative efforts can accelerate the deployment of thorium in PHWRs, addressing the global demand for clean energy and ensuring energy security. By focusing on thorium resources and PHWR expertise, India can play a significant role in the energy transition and achieve both domestic and global energy security goals.