what is the need of spending approximately 5 billion $ on 5 batteries of S-400 ?? just 5 are not enough for INDIA . the range of Russian s-400 is 400 km , but range of export version of s-400 is only 250 km ,that means we can not get (48N6) missiles with speed of Mach 6.2 , and range is also medium . they will not give technology , we can not get get s-400 before 4-5 years as they have to deliver s-400 to both Russian as well as Chinese forces before they can give us . on the other hand we have Akash Mk-II ,Barak 8 , Pradyumna Ballistic Missile Interceptor , Ashwin Ballistic Missile Interceptor etc . as Russia is not selling S-400 to INDIA what are our other options ?? Cant we make our own Air- deference system comparable to S-500 with the help of Israel , in the next 8-10 years ??