Acquiring nukes seems like the best way for any country to protect themselves against outside interference.
We know that as soon as Gaddafi decommissioned his nukes, Libya was targeted and invaded. If Iraq actually did have nukes, the USA wouldn't have been so brazen to invade.
China, Russia, and North Korea's acquisitions of nukes are also some of the main reasons why they are not easy targets for direct US invasion.
If Iran had nukes, it would drastically limit Israel's ability to indiscriminately attack Iranian assets.
Western policies against nuclear proliferation always seem to target the countries that need them the most to ensure national sovereignty, and never refer to their own nukes.
For example, they always fearmonger about "rogue states" like North Korea getting nukes, while being perfectly okay with Israel's own nukes. It might be best if these policies are ignored entirely.
I think the biggest reason why all countries should have nukes is that there is no way to guarantee that any one country doesn't have nukes, and just isn't telling anyone else.
For instance, there is no way in all hell the US will ever give up its nukes, unless the leadership gets blown to kingdom come first or they get overthrown.
If no one had nukes, all would be well and good. But if one country has nukes, everyone should have them as deterrence.
That makes sense, I just think about all the times nuclear war was accidentally started when effectively only two countries had nukes. The risk of an accident or a lapse of judgment happening when some two hundred countries have nuclear weapons is magnified significantly.