If it's uncertain whether a test has occurred, must be 50% confidence or greater. The list of countries that have already tested a nuke:
The United States
Russia (technically all tests were under the Soviet Union, but I'll count it)
The United Kingdom
France
China
India
Pakistan
North Korea
Israel
South Africa
1,000
3.00@IsaacKing Supposing that Israel detonates a nuke by EOY 2024, and is the only country to do so not clearly known to have done so before, will this question stay open until the linked question resolves?
Anyone have a good article to link on the potential candidates?
https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests has a list of countries that previously detonated a nuclear weapon, and Israel is listed as having an "alleged" test. Cases like that could make resolution tricky potentially.