What prevents me from owning WMDs?

I heard that it’s technically legal for the average American citizen to own military-grade weapons including WMDs. I have been thinking of obtaining a nuclear missile, purely for defensive purposes. What is preventing me from doing this?

Cost, (covered) storage space, and availability of fissionable materials.

I don’t think the original statement is necessarily true, that it’s legal to own ‘all’ military hardware.
But nothing at all is stopping you from making all the poison gas you want to make. Do it safely.
Creating a weaponized disease is more difficult, but should be possible if you study. Nukes aren’t cool enough, everybody will think you bought it.

Ever hear of David Hahn? I know he didn’t build weapons but he did attempt to build a nuclear reactor.

Biological weapons:

Chemical weapons:

Nuclear weapons:

Although I can’t find anywhere what the penalty for developing, manufacturing, producing, acquiring, receiving, or possessing of an atomic weapon is.

Nuclear weapons: All fissionable nuclear material in sufficient quantities to make even so much as a low-yield fission bomb are controlled by the Nuclear Regulatory Commission and the US Department of Energy, so you can forget that. Even if you have a uranium mine the enrichment process is arduous and isn’t a small operation, requiring certain things that would give you away were you to try to get them (aluminum tubes, anyone?). Everything else you might need to build one is otherwise available, including the explosives. It’s just physics, and while the specifics might be a secret a physicist ought to be able to create a workable model.

Biological weapons: The first requirement is a suitable pathogen. The second requirement is a laboratory of sufficient size to reproduce it. The third requirement is a delivery system, and the fourth is a long-term storage. All of them exist, so the only thing stopping you is access and money. Good luck getting Ebola from the CDC, but anthrax is possible.

Chemical weapons: Much the same as biological weapons. It isn’t exactly hard to synthesize ricin, for instance.

But you want to know what’s stopping you in the sense that anyone actually cares about your Dr. Evil-type plan, don’t you? The governments of the world reserve the right to possess WMDs to themselves, and the US government would be all over you in a heartbeat were you to attempt to make one yourself and they found out. Aside from that, knock yourself out. You’ll never build a nuke, but aim lower and the world is your oyster. Just don’t get caught or you’ll be spending the rest of your life sleeping on a concrete bed by yourself at ADX Florence.

The OP was meant as a joke. Let’s eliminate the creation hurdles now and say Russia is allowing me to buy a MIG with full, active weaponry. Am I still held back legally?

It depends on which MiG with which weapons and which state you live in. Fully automatic machine guns are banned so you couldn’t own the GSh-30-1 30 mm cannon from a MiG 29.

Bombs and missiles in theory can be registered as destructive devices and owned by civilians in some states.

[Moderator note]
(a) GQ isn’t the forum for jokes
(b) Your question (“Am I still held back legally?”) was answered rather comprehensively in post #5.

I’m closing this down. If you want to continue the discussion, feel free to either start a debate about it in GD or a general chat in IMHO.
[/Moderator note]