The issue is that what you end up defending is the right of more malicious actors to acquire technology from the US below cost through low-cost, high-yield hacking.
Do I? Or do I just not help to murder civilians on the other side of the planet? How can you be so sure that I’d only be helping the good side of the DoD?
From my point of view, both of you are right and wrong.
Being a conscientious objector to war is not the same thing as aiding an enemy. However, Defending against hacking is different from providing for offensive weapons.
In other words, defending government institutions takes precedence over the policies of government institutions. The policies are decided at the ballot box.
Let's assume there is no good side of the DoD. Let's assume that the military is 100% teeth-gnashing devil dogs with nuclear weapons. Which is what they aspire to, I assure you.
Two things, 1) whether they have a $700 budget or $700B budget, the DoD executes the orders of elected civilians.
2) Don't you still want to make it as expensive as humanly possible for other countries to get the plans to those weapons? Even if you live in Paraguay, rouge states with nuclear weapons increase the cost of international economic collaboration and thus decrease your quality of life. Securing the US Government's weapons information is in your best interest.
I did answer your questions. Perhaps I didn't convince you to reject your previously held views, but I did answer your questions.
> How can you be so sure that I’d only be helping the good side of the DoD?
I answered this by asserting your premise, the DoD has a good side, is unnecessary. I further allowed for the possibility you're not even American.
> Do I [end up defending the right of more malicious actors to acquire technology from the US below cost through low-cost, high-yield hacking]?
I answered this by posing the leading counter-question, "Don't you still want to make it as expensive as humanly possible for other countries to get the plans to those weapons?" And that appear to be the fairly strong position it is, considering I rejected your requirement of there being anything good about the DoD, and further rejected any implication that you're even American.
Then you’ve superficially answered the literal questions without actually getting at the underlying point.
The point is this: if I help them, how can I ensure that this help goes towards things like preventing other countries from obtaining nuclear weapons, and not blowing up weddings?
It's offense vs defense, and in this situation, those are highly separable domains.
Concretely, blowing up weddings is a failure of guidance systems, that's an offensive problem. Those are avionics and fire control problems, not network security problems. Avionics and fire control are highly specialized domains. You don't accidently write some code that helps with those problems. They have their own languages, their own compilers, their own chip architectures. The developers work in places you hear about on the History channel, like China Lake.
Conversely, the defensive work of improving the network security that protects the plans and software for offensive systems, including those avionics and fire control software repositories, is good for everyone not just the rabid dogs of the DoD.