Since Lee Harvey Oswald had such an obsessive and intense relationship with the Soviet Union and communist values, it is possible that he could have been hired as a KGB agent to assassinate Kennedy. After leaving the marines, he tried to defect to Moscow, but the Soviet Union placed him in Minsk under the surveillance of the KGB. Russia knew about Oswald's interest in communism and hatred for American politics, so he would have been an ideal candidate to hire for an assassination. He also had above-average shooting skills, which he learned in the marines. Given the political turmoil at the time, it is possible that Oswald was working with the Soviet Union to assassinate JFK.
Lee Harvey Oswald would have been a terrible option for Russia to hire as an assassin. He was already on the U.S.'s radar for being court-martialed twice while in the marines and showing interest in communist ideals, so it would have been difficult for him to go unseen. The United States had high tensions with Russia during this time, so to hire Oswald as a KGB agent to assassinate Kennedy would have been too obvious and risky.
[P1] Lee Harvey Oswald wanted to live in the Soviet Union and supported communism. [P2] Russia knew about Oswald's shooting skills and interest in Russian politics. [P3] The KGB monitored Oswald when he was living in Minsk. [P4] Therefore, the Soviet Union hired Oswald to assassinate JFK.
Rejecting the premises
[Rejecting P4] There is no evidence to support this theory.