What are some examples of an "industrial" (or pre-industrial) nation using "industrial" technology to defeat a "post-industrial" nation using "post-industrial" technology?

Let me introduce by saying that this question is inspired by the real world example of the Viet Cong using industrial technology (like rifles and machine guns) to defeat the United States (which was using post-industrial technology, like helicopters). Apparently there were several wars that happened like this, with industrial technology being used to defeat post-industrial technology. What are some examples of this, and do you have any theories on why industrial technology can be better than post-industrial technology in some situations? Or why this doesn't happen more often?<br><br>Thanks.