Reev Jax retired from the UEE Navy and started up the PMC known as Nexus Corp with several other ex-UEE officers.
While still keeping a military style structure Nexus Corp allows for a level of freedom and flexibility the UEE never did. This is something Reev Jax really enjoys about being in a PMC.
Reev Jax aims to keep his good standing within the UEE and will not take jobs that could damage that. There is however a bit of a grey area in this as well. Not all parts of space are under UEE control.