I believe think tank already knew about this situation 3-4 years back ..maybe that was the reason to purchase S400 knowing it would cause strain in relationship with umrica.
Nothing is lost as of yet as long we have plan and we work on it
Tejas Mk1 will be hired in number which will at least fill gaps in our defensive capabilities. That along with S400 and Kusha should be able to shield us
Problem is with our offensive capabilities.. that will take about a decade to replenish.. Mk2 and Amca is on paper and computer
MRFA is also like a carrot , don't see it materializing in near future unless umrican do something unexpected .