[ramanujan]

Hmmm. My point is that innovation speeds up dramatically during wars, in part because the involvement of dot.mil organizations can supersede the regulations imposed by dot.govs.

Taking your points in turn:

1. August 1939 in Nazi Germany wasn't exactly peacetime :) They were already planning to invade Poland. I believe it's pretty well established that aircraft development slowed between the wars but really got underway again with WW2 and then the Korean War.

http://www.ww2pacific.com/jethist.html

2. The Autobahn was arguably a peacetime development (though very useful for war), but it's inarguable that the US Interstate Highway System was developed for defense purposes.

3. Would computer networking have happened in some fashion? Probably, but DARPA saw it as a national security issue and cut through various kinds of red tape. Fiber could be laid across huge swaths of the country without environmental impact statements or FCC involvement. It's hard to say what would have happened without sponsorship from one part of the government.

[WalterBright]

1. Heinkel's jet airplane development was not funded by the government, as the Nazi government saw no military purpose to jet aircraft. They only got interested after it was flying.

2. Both the German autobahn system and the US interstates were partially justified by military use, and both were done in peacetime.

3. Computer networking did happen independently from the ARPAnet, and it did cover the entire country, both with dedicated lines and piggybacking over the phone lines. All the networks I mentioned were national (and even international) in reach. Everyone with more than one computer wanted to connect them together.

[WalterBright]

I should add that in Great Britain as well, the government did not begin funding of jet engines nor jet aircraft until after government officials saw flying jet aircraft.

In America during WW2, the government told Lockheed to halt their dev work on jet engines and concentrate on piston engines. Flying jet aircraft (from GB and Germany) again changed their mind.