The Terminator - Ending Explained

The Twist: The central twist is that Kyle Reese is John Connor's father. He fell in love with a photo of Sarah given to him by John, who knew all along that he was sending his own father to his death to ensure his own conception.
The Ending: Reese dies fighting the Terminator. The Terminator is stripped of its flesh and chases Sarah into a factory, where she crushes it in a hydraulic press. A pregnant Sarah travels to Mexico, recording tapes for John. A boy takes a polaroid of her—the exact photo Reese will own in the future—confirming the loop is closed. She drives toward storm clouds, symbolizing the coming war.

The Time Travel Paradox: Critics often debate whether the film represents a Causal Loop (Bootstrap Paradox) or a branching timeline. The prevailing view is a loop: Reese is John's father, meaning the future caused the past, and Skynet unwittingly created its own enemy. Another interpretation views the film as a Technological Allegory for the Cold War, where the fear was not just of the 'other' (Soviets) but of the weapons themselves (nuclear annihilation) becoming the true enemy.