Subject: Re: Jamming and spoofing GPS
I can't help wondering whether it would be more cost-effective to base a missile (or drone) defense system on GPS jamming rather than interceptor missiles.

Need both. Precision guidance typically relies on GPS--although an internal guidance system could be accurate enough to do the job (hit target). GPS would be cheaper to build.

US long-range high-precision artillery uses GPS (in the shells?) to be highly accurate. No GPS and they lose that accuracy.