After the Ishval Civil War, Roy was assigned to the military headquarters at East City. It looks like he was regarded a war hero because of his services in Ishval, and was promoted to the rank of Lieutenant Colonel. It was at that time when he offered Riza Hawkeye a position as his aide and right-hand woman, as an act of redemption for betraying her trust (the trust she placed on his use of her father's alchemy) during the Ishval War.

Approximately one year after the end of the war, Roy and Hawkeye visited Resembool in search for potential national alchemists. He had information about a couple of alchemist brothers, the Elric brothers, he may be able to recruit. He had no idea that those brothers were mere kids and were not in high spirits at the moment.

Looking for them, Roy found in their house something which was without doubt the result of a human transmutation attemp. He was horrified by it, and hurried to find the ones responsible for it. At Pinako's residence, he then met a broken Edward Elric with an arm and leg missing and a big suit of armor, in which the soul of the younger brother, Alphonse Elric, was sealed.

     

After his first reaction, which was of anger to see such young kids ruining their lives so foolishly, he sat down and made them an offer. He'd introduce Edward to the higher-ups and ask them to allow him to take the National Alchemist examination, even at such a young age. Of course, Edward would have to recover before that.

Doing this, Roy was actually giving hope to the Elrics. Though Edward would become the military's dog, he'd also have access to research texts and lots of priviledges that come with the rank (all National Alchemists start as Majors right from the beginning). This way he may be able to find the knowledge needed to recover their original bodies. Either way, Roy makes it very clear that it's all Edward's choice to follow that path.

A year later, Roy is already a Colonel and Edward goes to East City to see him. He has replaced his missing limbs with automail and is now fully recovered and ready to become the military's dog. Roy & Hawkeye see Edward to Central, where he passes his National Alchemist test.

Of course, no one has to know Edward and Alphonse committed a taboo by trying to revive their mother, or Ed's license will be annuled. What Edward fails to notice is that Roy has no intention whatsoever to let his secret slip, even if he says so in order to keep him in line. Unfortunately, Edward has still a long way to go till he realizes fully just what a big ally is Roy to him and his brother.

Till then, Roy and the Elrics' paths are different ones, as they have goals of each own. Which doesn't mean those paths don't converge from time to time, while Roy is always watching over the brothers in any way he can.