If India and China cooperate, a chunk of military budget could be diverted to economic development. China has been an open economy for nearly three decades; India followed in the last two decades. China managed to tot up a double-digit growth, enabling it to become the fourth biggest economy in the world. India has been doing 5-6 per cent till recently. Had they cooperated, they could have saved more resources for the advancement of their societies.
Again, if Indian and Chinese economies were better off, their people could have afforded more goods and services that the other has to offer. Because of their proximity, despite the Himalayas between them, these goods and services could have been transported at the least business cost.