Arsalan, I really do not know if you will ever understand it? But I still will give it a try.
India is a subcontinent, geographically closed and compact "Nation". Tamil Nadu in the extreme south can not remain unaffected by whatever happens in Afghanistan or Punjab. Be it environment, climate, politics, religion, famines or prosperity - it all effects the entire subcontinent. Be it Turks, Mongols, Huns, Kushan or Arabs, any thing that started in Sindh ultimately spread upto Assam and Tamil Nadu. Same was the case with Buddhism, same with Hinduism, same with national movement for independence. Politically there might have been different units but in all other respect they are almost as one.
So whatever happens in Pakistan, India gets effected. What ever happens in India, Pakistan can not remain aloof. That is why we Indians are worried the moment you have US bases. Chinese occupation of Pakistan is going to give us lots of headaches. Do not think that invasions in India happened from West only. Ashoka, Kanishka, Pals and many king, lately Sikhs invaded and captured present day Pakistan from East.
And now Modi will repeat the history of Maharaja Ranjit Singh. Be prepared. Some Mohiyal General of Indian Army may retake the kingdom of Raja Dahir by capturing Sindh restoring glory of Mohyals.
And do not dream of Chinese capture of any part of India. If it ever happens, it is going to happen after they have completely taken Pakistan.