India’s ambitions in electric vehicles, wind energy and defence manufacturing all run through the same narrow bottleneck: heavy rare earth elements such as dysprosium, terbium and yttrium, the materials that make permanent magnets work under heat and stress. Almost all of them are refined in China.As New Delhi looks to reduce that dependence, two of the most consequential upstream sources of these minerals sit not in Australia or Africa, but close to home — in Myanmar and Laos.A quiet buildout next doorMyanmar’s Kachin State has supplied China with more than half the value of its heavy rare earth imports in…