No, but they certainly helped cover it up. As did the Kennedy family. Probably to cover up the Cuban assassination plots and CIA incompetence.
If the MIC was behind the assassination, no Kennedy would have dared run for political office. The MIC could have easily leaked stories about JFK’s marital infidelities or the secret deal with the Soviets to pull US missiles out of Turkey through Mockingbird and it would have damaged JFK’s chances in 1964.
Note that after the assassination, US nuclear strategic warheads peaked in 1965 while the Soviet’s stockpile continued to grow and surpass the US. The Vietnam war was escalated but conducted in a feckless manner, mostly by people selected by JFK. RFK continued to support the war until at least 1966 when it was starting to go south.The “dangerous” Limited Test Ban Treaty remained in place. The MIC concocted and elaborate assassination plot that had to involve dozens, successfully carried it out and successfully covered it up but then still lost ground?
Based on asking “cui bono?” after the assassination, the benefits accrued to those who who would be expected to be behind the Cuba, LBJ or Mossad theories. The sabotage/assassination plots against Cuba stopped and there was no invasion. LBJ gained the presidency and not removed from office due to the corruption investigations. Israel was able to continue its nuclear weapons program unmolested, watchdogs dragged their feet on the NUMEC uranium theft and the Israel escaped RFK/Fulbright attempts to get them registered as a foreign Lobby.