Executive order: Relocation was a order straight from the NCR senate after the Second Battle of Hoover Dam.
A couple weeks after the Second battle of Hoover Dam, the NCR Senate started to clear things out with the many locations they haven't focused on. For example, giving aid to Mojave towns, establish refugee camps for Legion refugees, and much more. But they soon started to check on their borders. And after the NCR Senate saw what happened to Nelson and seeing all the Legion Raid camps on the borders, the NCR Senate talked about re-establishing fortified borders. Executive order: Re-location was soon put out straight from the Senate. This would take NCR troops and put them in more strategic areas and on the border. The NCR drafted a few hundred more soldiers and established many new outposts. This helped the NCR a lot and this resulted in more towns joining them and more people traversing to the NCR.