It's unclear if Belarus and Kazakhstan really had nukes in the first place such that they could "give them up"—as with Ukraine, the nukes stationed there were Soviet nukes, controlled by Moscow.
South Africa does seem to be doing okay, though. It's not that likely to be invaded by Zimbabwe, and since the end of apartheid, a civil war is looking increasingly unlikely.
> Tokayev (...) went on to thank Russia for sending troops to help establish order.
> Russia's Defence Ministry stated that more than 70 planes were flying, around the clock, to bring Russian troops into Kazakhstan and that they were helping to control Almaty's main airport.
On the other hand:
https://en.wikipedia.org/wiki/Kazakhstan%E2%80%93Russia_rela...
> Kazakh leadership including Kazakh Foreign Minister Mukhtar Tleuberdi did not condemn the Russian invasion and abstained on the UN vote to condemn it, but at the same time they refused to recognize the Russian states of Donetsk People's Republic and Luhansk People's Republic.
> In addition to sending humanitarian aid to Ukraine, the Kazakh military increased spending and training. (...)
> Russia suspended shipments of Kazakh oil after Tokayev’s statements at the St. Petersburg International Economic Forum, where he stated that Kazakhstan considered the DPR and LPR as “quasi-state entities” and would not recognize them. On the other hand, in spite of some tensions, Kazakhstan's relations with Russia remain strong and mostly friendly, as shown by Tokayev's visit to Moscow in November 2022. (...)
> In 2022, Kazakhstan agreed to share the personal data of exiled anti-war Russians with the Russian government. In September 2022, Kazakh authorities detained a Russian journalist who was wanted on charges of "discrediting" the Russian military. In December 2022, Kazakhstan deported a Russian citizen who fled mobilization.
I'm no expert in foreign relations, but to me, this sounds like the relationship between the Trump administration and the municipal government of Portland, Oregon, not like the relationship between France and Germany, the relationship between Argentina and Brazil, or even the profoundly unequal relationship between the US and Canada. Tokayev can posture a bit about disagreeing with Putin, but Russia will punish him, and when push comes to shove, he depends on Russian military support to stay in power; and when Russian dissidents or draft dodgers show up in Kazakhstan, he arrests and deports them. (Contrast Vietnam-War-era US draft dodgers fleeing to Canada.)
Brazil holds the key technologies to develop it and the sixth bigger deposit of uranium (with only 30% of the territory mapped). The navy is even currently developing a nuclear submarine that will be totally based on local technology.
A nuclear submarine is also not what is meant by "nuclear weapon", although it is arguably a weapon and has the word "nuclear" in its name. The phrase "nuclear weapon" conventionally refers to "atomic bombs" and "hydrogen bombs", which are bombs powered by respectively fission and fusion. A nuclear submarine is just a regular submarine powered by a nuclear reactor. Brazil already has many nuclear reactors that are in some sense "totally based on Brazilian technology" and has for decades.
I only knew of the three commercial reactors, the third of them under construction for something like four decades and still far from done (and they are also mostly foreign technology AFAIK). So I went looking, and it does seem there are a couple of decades-old research reactors I didn't know about: https://pt.wikipedia.org/wiki/Lista_de_reatores_nucleares_Br...
I went to a state university in the US that had its own research reactor, and I thought their university hospital had another one, but it turns out they don't now if they ever did.