The retaliation to terror attack is not starting a war but funding similar attack on a larger scale in pakistan but instead of targetting low value civilian, we should target high value assets.
Size is on India's side so is amount of money we can spend on such operations, why would you push India to war(even if pakistan did not posses nuclear weapon) when we need economic prosperity to remove large number of Indian out of poverty. Winning a war wont guarantee that, but forcing pakistan to come to negotiation (without open humiliation but rather due to their own reason) will.