SpaceX wouldn't get anywhere without military contracts, not sure about Blue Origin.
Many other recent rocket startups have also went for DoD money.
Many other recent rocket startups have also went for DoD money.
And I wouldn't say they wouldn't get anywhere, yes they have military contracts, their bread and butter is more NASA though, and it's a stretch to not describe NASA as civilian so it's even more of a stretch to describe one of their private contractors as non civilian.
If you take the maximalist approach, nothing is civilian. Including this university supported rocket.
Similarly, USAF was major investor in making Starlink happen.
Computing got its start in the military, is Apple a military company?
Compare this with SpaceX where DoD funding was crucial or most of other US launch vehicles that trace directly to early ICBMs. Ariane was built by companies from defense sector continuing development started from ICBM work - but Arianespace was purposeful pivot into pure commercial, civilian vendor (though subcontracting to defense industry still).
As for nuclear, civilian reactors aren't much of offshoot of bomb production except for using the same physical processes underneath.
In fact, civilian nuclear reactors are just as much likely to consume plutonium in MOX fuels. All warhead manufacturing countries have separate, optimized production chains for plutonium.
What's the Pu240/Pu239 ratio in the most recently loaded set of fuel rods in any given moment?
It's literally why USA had been more or less legally trying to stop everyone from running highly-enriched fuels in reactor (or generally make itself a nuisance for projects that in turn require no enrichment at all, because that stops dependency on limited enrichment facilities).
High enriched U is a proliferation risk because it's easier to enrich to weapons grade.
Fuel rods that have been through a full fuel cycle are 'useless' because of the Pu 240.
Fuel rods that have been in a reactor for 1-2 years (present in every 'civilian' reactor at all times) are neither of these things. And contain weapons grade Pu that can be used if you have Pu separation facilities.
Spacexs first dod contract was in 2016. Spacex successfully landed their first falcon in 2015. They were already the company we know and 'love' prior to them getting any dod contracts.
Ultimately, first 2 launches the customer was purely military, and third launch by SpaceX was shared military / NASA / civilian client.
The previous Europa rocket had parts from ICBM.
As for liquid-fueled ICBMs - Soviet Union invested much longer into liquid-fueled ICBMs, including very heavy ones, something that paid off in keeping their space sector in expertise.