Why didn't the Indian kingdoms attempt to expand into Indochina?

by Betrix5068
Lich-Su

Though Indic influence is present in much of what was Indochina (the India part of Indochina), the two areas are quite distant. A massive block of land including Burma and Thailand separates it from the western edge of Indochina. These countries remained in a East and Southeast Asian sphere more than South Asia. The Vietnamese kingdom was a tributary of China. The Cambodians remained subordinate to both the Thai and Vietnamese kingdoms. And Laos did not exist before colonialism, it was just five small principalities, subordinate to Thai, Cambodian, and Vietnamese influence. The Indian state was absent, except for some commercial dealings in port cities. But even there it was Chinese merchants that held sway.