The threat of small drones in fact has very little to do with proliferation of affordable, commercially available drone technology allowing the metaphorical Akhmed the Technologically Adept Mujahideen to order himself a bunch of parts on Ali Express, throw together a dendrofecal-grade improvised loitering munition and try using it to blow up something important.
In reality ALL truly significant attacks with such 'improvised' weaponry that took place in last five years were either orchestrated or outright performed by state actors.
That's what you should be concerned about, mission-specific engineering and prototype warfare on part of hostile state actors as a new form of deniable operation.
It's flat out impossible to protect one's things of strategic importance against this sort of threat in any other way except addressing it on technological, organizational and doctrinal levels on all scales.
To illustrate my point, take a look into specifics of the guidance system of old Tomahawks, what do you see? You see a very, very hard customer for Air Defence which is extremely resilient to basically all tactical means of electronic defeat except the ones capable to outright functionally defeat it. It combines INS-assisted GPS with terrain and target recognition, allowing it to pull through the localized jamming without getting mission-killed or suffering unacceptable losses in practical performance.
The real fun begins when you realize that it won't take neither US nor Russia nor China much effort to cobble together a platform-independent functional analogue of Tomahawk's guidance system. Throw in great power militaries-level intelligence, planning, Ali Express hardware, suitably 'dendrofecal'-looking design and voila, a bunch of dendrofecal ghetto-Tomahawks executing textbook saturation attacks on your rival's strategic infrastructure, high-value assets, military forces and what not.
Would you like to know how do you combat the actual Tomahawks? Why, all it takes is radically changing the state of electromagnetic environment in desired ways on a five-digit figure of square kilometers, and very quickly.
I wish you greatest luck in trying to pull off that kind of tricks through any sort of tactical kung-fu
P.S. The above-written is simplified description of certain non-kinetic active measures of cruise missile defence of the Mordor's national IADS. Simply put, shit's real, boyz.
