Strauss and his sister were born in Israel, to American parents; the family emigrated to Canada and, eventually, back to the US when Strauss was a child, shortly before the global recall of American diplomats from Europe and the Middle East. They continued to move throughout Strauss' childhood in order to better facilitate his parents' work, and as a result Strauss learned two things early: how to command a room, and how not to get too attached to anything. Wildly intelligent but easily bored, Strauss continued to coast academically to his parents' vocal disapproval. He studied politics for a single semester at college before dropping out and joining the armed forces, more as a way of thumbing his nose at his father than out of any real interest in serving his country.
The military gave Strauss the challenge he was seeking, and he successfully chased its faint praise all the way up to the rank of Private. From there, he went on to qualify as a member of the US Army Special Forces. Born out of the WW2-era Psychological Warfare Division, the Special Forces branch of the US military was formally created in 2054 as a response to the European-Middle Eastern War and the socially-transmitted New Plague.
Initially focused on recruiting operatives with cultural and linguistic knowledge, the US government used SF units mainly to conduct unconventional warfare in China, Alaska, and the Middle East. With his ability to speak fluent Hebrew and Arabic, as well as parts of his upbringing having been spent in Canadian Quebec, Strauss had the uncanny ability to conform to virtually any conflict the government dispatched him to. Despite this, his attitude remained a problem throughout his entire military career; many of his peers joked that they were lucky Strauss had so graciously chosen to join the United States military, given that he seemed to be superior to everybody else on the planet.
By 2070, tensions over the Anchorage Front Line had led the US government to dispatched its armed Special Forces to lay the groundwork for the eventual annexation of Canada. In 2074, Strauss was deployed along with the rest of his unit to join the invasion of mainland China. With the United Nations having been dissolved, and most other countries busy dealing with the global lack of food, fuel, and other resources, there was remarkably little oversight when it came to the US forces in China, and much of what the US Special Forces accomplished in this time remained redacted even after the Great War was over.
The use of the first T-51b Power Armor units in the war effort turned the tide in favor of the US, and by June 2076 the conflict in China was all but won. Strauss was recalled to the States, where he moved in with his pregnant sister on the outskirts of Boston. The following year, a global exchange of nuclear arms resulted in the near-total destruction of the continental US. Strauss' service bought him a place in nearby Vault 111, along with his sister and her infant child, and they were able to escape the nuclear fire by a scant few minutes. However, Vault 111 was actually a government experiment in long-term cryogenic suspended animation, using the civilians of Sanctuary Hills as test subjects.
When he finally awoke from "decontamination", Strauss discovered that it was actually 2287: a full two-hundred years after the nuclear strike that had driven them to seek safety in the Vault. He subsequently discovered that an unknown individual had broken into Vault 111 some years earlier and abducted his nephew, Shaun, before the rest of the pods' life support. Unfortunately, the assailants' attack had left Strauss' sister mortally wounded. She died shortly after he opened her pod, though not before making him promise to find Shaun's kidnappers.
Strauss eventually emerged into the Commonwealth wasteland, where an initial exploration of the surrounding area revealed a strange, makeshift outpost, marked with a mysterious symbol. Believing this to be related to his nephew's disappearance, Strauss successfully tracked the symbols into Boston, where he discovered a group known as the Railroad sheltering inside the crypt beneath the Old North Church. The Railroad didn't know who had taken Shaun, but they could point Strauss in the direction of some people who would. In return, they planned to make use of his unique skills as a pre-war Special Forces operative to bolster their position in the Commonwealth. Mixing good old-fashioned spycraft with a humanitarian ethos, the Railroad enlisted Strauss' help in rescuing escaped robots - or "synths" - whilst evading retaliation from the shadowy Institute.
A note on Ships: Briefly summarized, Strauss/Deacon is basically a case of two people where both are assuming the other one is the sidekick; Deacon technically outranks Strauss, making Strauss' pre-War rank meaningless, and neither of them seem capable of properly outfoxing the other. But there can be nobody else for either of them, emotionally and intellectually. The more precarious their situation gets, the more fiercely protective of each other they become. Strauss is unlike many of my other Fallout protagonists in that his moral compass is pretty... flexible, so I can absolutely see Strauss/Kellogg happening. It wouldn't be pretty, but it could happen. Strauss/Maxson is another potential option in an array of unhealthy 'ships. Arthur has a way of seeing the world that Strauss once described as "young", and he's enough of a rat bastard to want to seize that kind of bitter innocence between his teeth.