Why India should have the S-400 missile system ? from which country India should Buy it Russia or USA.

S-400 missile system

Modern world partnerships are mainly based on Financial and any benefits. There is no place for any emotions. And we know

India

is surrounded by country like Pakistan , China . These country are always looking for any opportunity to capture parts of India , or looking for some opportunity to attack on India . So India started making it's defence system powerful , Now India is world largest imported of defense systems . So we are talking about s-400 missile system . First what is s-400 ?The S-400 Trimuf can engage all types of aerial targets such as aircraft, ballistic and cruise missiles, unmanned aerial vehicles (UAV), which are within the range of 400km, at an altitude of up to 30km. It can track 100 airborne targets, including super fighters such as the American F-35, and can destroy six of them simultaneously. So basically it can destroy all type of enemy .Once India deploy S-400 along the border of India-Pakistan and India-China the Balance of defense power in South Asia will changed. S-400 will increase India accessibility ,  Pakistan Multiple Posts can be easily accessed by India , even India can easily destroy multiple Air fighters. But USA never want India to buy S-400 from Russia , there are multiple reasons for it . Americans are successful in the world market more with their weapon sales and military hard wares. So any country who is big exporter of weapon is an enemy for America . Now If India purchase S-400 missile system from Russia , it will increase a stronger relation between India and Russia .Now a question is , is it good to buy such costly missile system ? Let us understand this . India has already missile system but none of them are solving our main problem , we can not target our enemy from surface to air easily .We have a couple of surface-to-air missiles but none of them are correct solutions to the problems that our military is facing . Many peoples are raising question why India is not making missile like S-400 instead of buying it . So my answer S-400 is very advance missile system , even China and USA do not have such type of advance missile system . Russia took 20 years around to deploy S-400 for Russia . And If Talk about our DRDO they have already various project in pending status , so we can not expect from DRDO to start a new project like S-400 .India has only way to make it's defense stronger and independent , just buy few missile and rest of them manufacture in India with help of seller country. India will learn technology and In future It can be Independent from defense purchase .