Actually gov't only funded scientists to put together the atomic bomb. Atomic power plants were most certainly developed and build by private industry. As was all the infrastructure needed to do those projects you mentioned.

Govt can do deeds, but is much less efficient at performing tasks. See the Post Office, or any other bureaucracy.

The military is a different case altogether, noone has ever argued that the gov't has no place building a military.

Also , private enterprise did save the world in WW2. There is a reason we ended up innovating in weapons, and simply producing more guns, bombs, planes and tanks than the Axis. Our fundamental economic system was simply superior to National Socialism.

For who could be free when every other man's humour might domineer over him? - John Locke (2nd Treatise, sect 57)