Not sure if it considered a "international law" but there are treaties about nuclear testing :
https://en.wikipedia.org/wiki/Nuclear_weapons_testing#Treaties_against_testing
Like this one :
https://en.wikipedia.org/wiki/Comprehensive_Nuclear-Test-Ban_Treaty
Now, I'm curious about what the community will think if you put it on metaculus, could be interresting.
A thought occurred to me, and it's so logical, I concluded that it must be true.
Is this satire?
Russia will detonate a nuclear weapon in Russia. In other words, Russia will do a nuclear test. Like North Korea did.
With (literally) a nuclear option, pushing the nuclear button is a last resort.
The path there is through various escalations, without any individual step being too overt.
For example, if Putin wants to demonstrate their willingness to use nuclear weapons, he can:
A thought occurred to me, and it's so logical, I concluded that it must be true.
Russia will not detonate a nuclear weapon in Ukraine, fearing repercussion.
Russia will detonate a nuclear weapon in Russia. In other words, Russia will do a nuclear test. Like North Korea did.
As far as I know, there is no international law against Russia doing a nuclear test. Russia is a recognized nuclear weapon state of NPT, unlike North Korea. The test will give weight to Putin's words that he is not bluffing.