One of the concern when traveling is the safety. It is better to stay prepared than being exposed to danger. Clearly, the places that have been already declared danger zones are not allowed to be traveled on. The nation will not allow their people to travel to dangerous places like nations who are in a war. they can issue a travel ban to those countries. There are also other areas that have the possibility of a terrorist attack and so they are temporarily included in the banned countries.
It is best to follow the recommendations. There are many places though on earth that are free to travel. Also in one country, there are areas that are not banned as they are far from the place where war is happening. It is still open then to tourists. That is why when you travel, it is best to check the place first in terms of its safety. When it is not much safe then it is better that you travel with a group. Having someone when traveling is safer but there are places that security is better though it is not 100% guaranteed.
There are unprecedented circumstances that could happen. But being with someone reduces the risk. Take note also of the travel advisories and the warnings that are issued by authorities. It is best if you know what could you expect so you can make some adjustments. There are many places around the world that are beautiful and good to explore but because of the danger, it is closed to tourists.