There are really only three countries that could trigger a third "World War. Those include the United State, Russia and China. However, there are nine countries with documented nuclear arsenals. The United States and Russia possess significantly more nuclear warheads than any other country. According to the Federation of American Scientists as of 2022, Russia possesses 5977 warheads, while the United States has 5428. While not all of these are deployed there are still an estimated 2000 active warheads on ballistic missiles ready to be launched at short notice.