Yeah, it's always a contest to stay ahead. Armor led to anti-tank weapons which led to ablative armor which led to molten warheads which lead to reactive armor, etc, etc. I remember when I first heard about reactive armor and couldn't decide if it was brilliant or idiotic.

You can block GPS easily enough, although motion sensors can help guide a drone too. You can have IR cameras but your targets can shoot IR light into the sky to mislead the drones. I'm not sure if you can send enough raw EM radiation into the sky to disable cheap drones - wouldn't surprise me.

It might work once, like the sneak attack on Pearl Harbor, but never again.