in certain areas. Like Tom points out, the money and resources diverted from other pursuits might well have retarded development in other areas. Lacking Mr. Peabody's "Wayback Machine", it's rather hard to explore alternative histories and know for sure how things might have been different.

Yes, the Internet is an outgrowth of Arpanet, which was developed to provide reliable communications even during a nuclear attack.

Nuclear power, both in the form of weapons and powerplants, came first to the military.

While the idea of jet propulsion preceded the war, the threat of war is what spurred its development.

Radar also preceded the war (barely) but was developed precisely because of the threat of war.

Personally, my favorite example is antibiotics. "NOVA" did an excellent show on this topic several years ago. It's hard for us to conceive of a time when a simple infection could be so dangerous as it was in the days before antibiotics. While Flemming discovered penecillin in 1928, it wasn't until WWII that the resources were made available to move penecillin from labrotary curiosity to large scale use.

Today, a lot of resources are still being used for military purposes. However, a great deal of R&D also is driven by commercial rather than military goals.