Yes, a lot of equipment is unaccounted for because most field commanders don’t want to take the time for documentation. Yes, in today’s armed forces that equipment has become really valuable. And it eventually resurfaces because there’s really no value for most of this stuff on the black market. Maybe the solution is to put GPS tracking devices in the equipment. If they can track a Canadian goose with a tag around its leg, they ought to be able to track a $200,000 piece of military hardware.
A LOT of high-end equipment is already equipped with GPS tracking and active RFID systems. Engines, especially aviation turbines, munitions containers, etc.
Tracking equipment once it’s removed from the packaging is another issue.