Regarding the FGM-148 Javelin, following the analysis of the use of the weapon in the Ukraine-Russia war, I discovered a weakness, which can be “rectified” in a future model.
Capture of these weapons by the enemy can be used against if the Command Launch Unit (CLU) is equipped with a GPS tracking device.
As a passive protection, very easy to implement, the CLU can be programmed to operate only in a predetermined geographical area (GeoFence). Upgrading the operating area can be done automatically by various methods, by default maps (loaded into memory), activation key, etc.
Self-destruct CLU, if the unit is attempted for use in a prohibited area, if an invalid code is tried 3 times in a row, etc!
Another method of passive protection: A CLU that has not been used for a while can be deactivated and must be reactivated by a key that can be a master-key, device-key (per device) or periodically expires and must be renewed.
As an active protection, but more difficult to implement, the CLU can be deactivated, using satellite radio signals … or it can be used to find the exact location of weapons, and consequently measures can be taken to attack the location.