Myanmar's President Min Aung Hlaing has personally assured Prime Minister Modi that Myanmar will not allow its soil to be used against India — a landmark pledge that goes directly to the heart of India's most pressing eastern security challenge. For decades, insurgent groups operating in India's Northeast have trained, sheltered, and rearmed inside Myanmar. Indian security agencies have repeatedly flagged the role of Chinese-made weapons flowing through Myanmar's conflict zones to these outfits. The assurance therefore carries a strategic signal aimed squarely at Beijing. But security is only one part of this story. Myanmar's Kachin and Shan states hold vast rare earth deposits that China currently monopolises. India's stalled Kaladan Multi-Modal Project and the India-Myanmar-Thailand Trilateral Highway — both critical to its Act East ambitions — need Myanmar's cooperation to survive. With China building competing infrastructure, Delhi's window may be narrowing fast.