Skynet seems to think so. In Terminator 3 the T-800 Model Terminator informs John Connor that the events of T2: Judgement day did not prevent the creation of Skynet but only delayed it and that the creation of Skynet is invevitable. This one of the reasons I like the Terminator movies, the concepts of time travel that comes in to play and Predestination Paradoxes or Causality loops that are used in the story.
Is the creation of Skynet inevitable? Well according to the story it is the future that creates Skynet (oversimplification), Skynet is developed out of technology from the future. When the original T-800 is sent back in time to kill Sarah Connor ( first Terminator movie) it is the parts that remained from that terminator that advanced the R&D at cyberdyne industries. In T2 these parts are destroyed and the creation of Skynet is delayed, but it does still happen (T3: Rise of the Machines.)
Skynet creates itself essentially, by having sent the terminator back in time, this is the crux of the Predestination Paradox. Well What if it doesn’t create itself? In Terminator Salvation Skynet has a kill list that is made evident early in the movie, top of the list Kyle Reese a teenager in post apocalyptic LA. Why is he on the list, presumable if you kill Kyle Reese, John Connor leader of the resistance will never have existed, b/c Kyle is the father of John Connor who sent him back in time to protect his mother Sarah Connor from the orginal Terminator (first movie) Predestination Paradox… DUN DUN DUUUUN. However if Skynet were to succeed and kill Kyle Reese does Skynet kill itself… or would its creation still be inevitable?
If skynet succeeded and killed Kyle Reese, John Connor would never exist to lead the resistance, and skynet would not need to send a T-800 back in time trying to kill Sarah Connor. Since the T-800 does not travel back in time, cyberdyne advanced R&D does not gain access to future technology on which Skynet is designed. This could lead to a possibility where Skynet is not created, but at the very least causing another delay it’s “inveitable” creation.
It would seem Skynet has a Kyle Reese problem.
Or rather the writer(s) of Terminator Salvation… since it’s all make-believe.