1, 8 countries with nuclear weapons (time of first nuclear explosion in brackets):
The United States (45.7), Russia (49.8), Britain (52. 10), France (60.2), China (64. 10), Israel (late 1960s), Pakistan (72) and India (74);
Three of them are Belarus, Ukraine and Kazakhstan, which were separated from the former Soviet Union. Before the Soviet Union split, these three places had already reserved some nuclear warheads and nuclear technicians, and they had the conditions to manufacture nuclear warheads again. However, all three countries publicly promised to return Russia's nuclear weapons to the International Atomic Energy Agency and declared them as non-nuclear countries (they think it is safer this way).
3. Two countries are absolutely capable of producing nuclear warheads:
Japan: On the one hand, it adheres to the three non-nuclear principles (no possession, no manufacture, no import), on the other hand, it makes preparations in secret. It is generally believed that Japan is a quasi-nuclear country, which can produce nuclear weapons within one year and become the third nuclear power in the world.
Germany: Germany is the first country with nuclear technology. After the defeat, Americans took the lead in developing a nuclear bomb. There are now 25 nuclear power plants, and it is easy for Germany to possess nuclear weapons.
4. As many as 44 countries (regions) have nuclear programs, nuclear technologies and the potential to manufacture nuclear weapons.
Brazil, South Africa, Libya, Algeria, Argentina, Canada, Iran, North Korea, South Korea, China, Taiwan Province Province, Libya, etc.
The United States has deployed many nuclear weapons in seven western European countries, such as France, Britain, Germany, Turkey, Italy, Netherlands and Belgium.