The drones have inertial guidance and gps is used for corrections only. That means when the drone is guided to blow up the railway junction, maybe you throw it off a bit so it hits the apartment next door. Not necessarily a good plan. There was also the case of a drone being damaged by ground fire, and veering off course to hit an office building next to an energy junction that it was being aimed at. And the problem of all those people shooting small arms into the sky causes damage when the bullets fall. For these reasons, Ukraine has asked people to stop shooting at the drones -- the time to shoot down drones is when they are flying over fields towards the city, not when they are already in the populated areas.

You have the same problem with putting AA missiles in populated cities -- sometimes they miss and slam into an apartment/office building -- that has happened 3 times so far at least as publicly reported (most likely it happened more often). You are supposed put the AA missiles in defensive rings around your assets, not in your downtown area. Ukraine's problem is they don't have enough to deploy as effective rings -- e.g. they don't have a real AA system, and so they put the missiles directly in populated areas, in which case it's better to turn them off when the cheap drones fly by and save them for enemy jets. Those missiles are not cheap.

Really the drones are exploiting the fact that AA missiles are so expensive and there is a gap between the guy with a rifle standing on the hood of his police car and a $2 million Amraam. Even manpads cost far more than the drone. The production costs of one of these is about $1000 (although they are sold for 10-20x that retail) - using parts sourced from Alibaba. A cheap moped motor, a mirocontroller, it's really simple stuff. Like V1 [corrected] rocket tech. Israel is working on the "iron beam" laser defense, but right now, there doesn't exist a working defense that doesn't involve firing million dollar missiles at $1000 drones. It's something all the major powers should be investing in, and I'm worried the U.S. defense complex just isn't able to do "cheap" any more. Could they even design a system that could take out such a drone cost effectively?

The random Chinese consumer drones, sure. You could also just block wifi to knock out most of them too.

Current block military drones being imported from Iran are not vulnerable to GPS manipulation because they have backup inertial navigation systems.

After Iran steered an American drone using false GPS signals, the US also implemented inertial and celestial navigation systems. https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incid...

I'd assume the Russian drones would default to GLONASS