Peace between these two countries is ideal, and why shouldnt one want peace among human? But Im not sure if it is practical, either accept it or not, religion does play a role, Conflict between polytheist and Muslims is quite old, from age of prophet Noah, to prophet Ibrahim, to prophet Mosa, to prophet Muhammad (saw) (peace be upon them all), and it seems it will keep on going till this world is destroyed by the will of God.
I think before we Muslims go in to deal with mushriks/polytheists/Hindus, both sides need to consider this aspect of humanity.
India does not equate to hindu. India is not a hindu nation, it is a secular republic. It has some of the biggest populations of other religions too, in the whole world. It is one of the biggest muslim nations, the biggest Sikh nation, the biggest jain nation, and more. We also have tens of millions of Christians and Buddhists and others.
By the way, most hindus are not polytheists. There are polytheistic hindus, monotheistic hindus (the majority), henotheistic hindus, kathenotheistic hindus (especially in the days of the Vedic religion), monistic hindus (most clearly defined in advaita Vedanta - and as many would argue, monism is possibly the most powerful and philosophically influential version of hinduism) and even atheistic hindus (charvaka, mimamsa, samkhya and ajivika schools of hindu philosophy). Hinduism is really not one single religion, comparable to the Abrahamic religions. It is an all encompassing term for several philosophical schools of thought that grew in the subcontinent over millennia.
Also, your characterization of conflicts "between monotheists and polytheists since ages" is really unfounded. Most of the conflicts have been, and continue to be, between monotheists and monotheists. Has it never occurred to you that muslim-christian conflicts, muslim-jewish conflicts etc have occurred throughout the history of these religions? Why suddenly make it seem like an ancient conflict between monotheists and polytheists, when Israel and the Arab world and Iran are in a much more combustible situation, when terms like "crusades" and "jihads" and "holy wars" have been invented primarily to describe war between monotheists? There were no polytheists in the crusades, were there? When many muslim groups today call for jihad against USA, they don't have polytheists in mind, do they? None of the wars in Europe between muslims and Christians throughout the past millennium involved any polytheists, did they?
Anyway all that is irrelevant since, as I said before, India is a secular republic, and does not view its geopolitics or conflicts through the lens of religion. If others around us do so, we cannot help that. Whoever initiates a conflict with India, whether for religious reasons or some other reason, will be dealt with in the same manner. Our soldiers are only taught to distinguish friend and foe, not polytheists and monotheists. Our soldiers themselves may be polytheists or monotheists or monists or atheists in their personal beliefs, which is irrelevant to their soldiering.