|What do you need to have an effective (early) warning system against nuclear strikes? I would presume some satellite systems for detection of launches and some ground based (or sea based or airborne) radars for tracking incoming ballistic and cruise missiles as well as planes/bombers/UAVs. In modern times I would also guess some form of radiation detection system to monitor borders and coasts against a weapon being smuggled in would be needed. Is this essentially correct? If so, how much would this cost to build and operate and how many people would it require to build and run?
Another issue: How does one secure the system against being destroyed, which would leave on blind?