The US has a bunch of (classified) tech to make reverse engineering unusually difficult. It is also several million lines of complex code. Different countries have different builds of the software, with some features missing, degraded, or disabled. There are also regular capability upgrades with new software versions; the production versions of some software features are roadmap items still under development.

I suspect that by the time anyone was able to successfully reverse engineer it, it would be semi-obsolete, which limits the value in doing so. Playing catch-up requires taking a lot of aggressive R&D risks that European governments have traditionally been very uncomfortable with or which take far too long to execute.

Might be a good idea to spend a couple of million by setting up a small office of 10 people to work on it in the coming years.