Being a citizen in #C17 was not an easy thing, as the Combine was slowly pushing everyone to their limits with the agenda of converting them to their side.
It was a carefully calculated process that would either make one break and rebel or would lure them in with rewards to the side of Civil Protection and beyond, if one would have the guts to make the sacrifice.
As a metrocop, one would be sent to missions of increasing difficulty, and if one wouldn’t undergo the merge with synthetic robotics to their body, they would sooner or later meet their demise.
For the Universal Union on Earth, this was the filter that would give them the best soldiers that could be harvested for their great inter-galactic empire.