As Oswald himself wrote in his journal: "I am starting to reconsider my desire about staying. The work is drab, the money I get has nowhere to be spent. No nightclubs or bowling alleys, no places of recreation except the trade union dances. I have had enough."
"Ladies and gentlemen, please welcome ... Lee Oswald and the Trade Union Dancers!"
Yep, it was the lack of bowling alleys and nightclubs that drove him back to the USA, and back onto the path that would lead him to killing a president.
By all rights, at that point the USA should have told Oswald to go fly a kite, trapping him in Russia where he could never hurt a pinko fly, much less the president. Instead, the United States let the wayward dipshit come home, presumably after a hearty round of "Told you so," and the USSR let him go, presumably because his lathe machine operating skills sucked.
So Oswald comes home and goes nuts, right? Not at first. First he tries to defect to Cuba, since everyone knows the second time is the charm. But this time the U.S. wasn't having it. A few weeks later, President Kennedy decided to visit the home town of a twice-jaded trigger-happy Communist newly enraged at being told he was trapped in America forever, and conspiracy theories notwithstanding, the rest is history.
"Ironically, I am actually three people."