Eli5: Why is it so difficult for countries to build nuclear bombs?

Question

I understand the technology is difficult. My question is more about how is it that some countries have achieved a nuclear arsenal and other countries are still trying? You’d imagine if the scientists and engineers of one country could manage it, those of another country would eventually get it too. Seems an odd convenience that the most dangerous weapons on earth are prohibitively difficult to make. So few humans are smart enough to make them that only 9 countries have achieved it?

In: Engineering

Answer 1

The most important thing to keep in mind is that most countries are _not trying_. Many could develop nukes if they wanted to — they have chosen not to. This choice is reinforced through treaties and a world situation in which they feel more secure not pursuing that path than pursuing it.

The technology itself does require certain hurdles but those hurdles are, by now, not so difficult that they are truly unobtainable even to poor or underdeveloped nations. If North Korea and Pakistan can develop nukes, then pretty much anyone can, if they are willing to spend the resources and time on it. But also, importantly, if they are willing to spend the _political_ capital on it: going down that road means either violating an important treaty (the Nuclear Non-Proliferation Treaty) or not being a member of it, and both of those come with significant economic and political consequences. Additionally, if you are trying to secretly build a nuclear weapon outside of the treaty regime, you risk calling down the wrath of other nations who, through war or sabotage, may try to stop you.

The technology is tricky, but it is not the factor that makes it prohibitive. Its trickiness just adds time and difficult, so you can’t simply say, “I want a nuke” and tomorrow have one. But it is not what keeps nations from eventually getting it. The technology is nearly 80 years old. It is not as hard as it once was.

All the sanctions and export restrictions do is buy you time. Eventually, any nation that puts in the resources and keeps at it can probably pull it off.