The Bright Republic enacted all kinds of policies to mobilize the private sector into contributing to its defense.
The government did not coerce mech pilots to fight, but provided incentives to those that did. Forcing those unwilling to fight would never work, as instances such as running away as soon as the sandmen appeared would always take place.
Right now, many Brighters still possessed confidence that their state could weather the storm. They were used to dealing with pressure due to their frequent wars against the Vesians, but that was not enough to explain why so many outfits volunteered to the front.
Everyone was looking ahead.
As long as the Bright Republic defeated the sandmen, it stood to gain immensely. The star systems of the crumbling Coman Federation and beyond were up for grabs.
The only issue was that all of them had been swept to a ruin by the sandmen and required centuries to rebuild. Even so, the payoff would be immense.