The end of our civilization can occur not only because of the war. Here are a few more factors that may well pose a danger to people.
Superulcan. This is an underground system that can break the continent. The main candidate for this role is now considered Yellowstone in the United States. According to scientists, such an eruption on the planet already occurred about 640 thousand years ago. Then the consequences included only the fact that half of America was covered with a layer of ash, and today they can be much worse: the death of the harvest, global cooling, the death of logistics and economics. Another option is the Campa -Flemra Supervolkan in Italy.
Asteroid fall. 66 million years ago, the asteroid chiksulub fell on the Yukatan peninsula. Because of this blow, earthquakes, fires and tsunami arose, and the sun was closed due to a layer of dust for years. As a result, dinosaurs were also killed.
Pandemic. Viruses that differ in high mortality are especially dangerous: like an ebola or bird flu. If one day a strain appears, which combines the infection of Covid and the mortality of Ebola, then the consequences can be terrible. Another direction of development is bioengineering. People can accidentally create a virus against which there will be no protection.

Global climate change. Since the beginning of the industrial era, the average temperature on our planet increased by about 1.2 degrees. It seems that this is a little, but because of this, Greenland and Antarctica glaciers are melting, the level of the ocean rises, entire regions become unsuitable for life. In general, it can happen that the climate will change beyond recognition.
Artificial intelligence. Its danger lies not only in the “ultrasound”, but also in the fact that even now the cyber attacks can be disabled by the Electric System of entire countries. It is difficult to imagine what will happen if the technological failure is affected by medicine, transport, and military sphere.