There are lots of countries today that really want to make sure that their countrymen are safe and sound from the dangers of the outside world. It is because there are times where countries do not agree with one another and this can cause problems with their relationships which can ultimately lead them to declaring war with each other. This is a fate that we cannot predict and we cannot stop most of the time, it is because most countries want what is the best for their country. That is why in cases of war, each country has their own military and weapons that they can use so that they can protect themselves from the weapons of their enemy. We are in an age today where technology has really become a major factor in terms of the weapons that countries use today.
Interested in building underground homes? Most weapons today are very sophisticated and can be used with deadly precision, but there are countries that still use cold war weapons like the nuclear bomb because it is still very dangerous and very powerful although very old now. It is because the strength of a nuclear bomb cannot be matched by the strength of the weapons of this age and if they can be beaten in terms of strength by newer weapons, the catastrophe and damage that nuclear bombs leave will usually stay there for a very long time and can make a certain place uninhabitable for life.
That is why when it comes to nuclear war, there are lots of countries that are building secret underground bunkers so that they can be protected in the case a nuclear bomb hits their area or country. It is because a nuclear bomb can really wipe out an entire city in just a blink of an eye. That is why nuclear bomb shelters are being built underground so that it can be well protected from the nuclear blast that happens above ground, not only that, nuclear bomb shelters are very strong and can withstand radiation and nuclear shockwaves too.
Nuclear bomb shelters are also designed to protect the people inside it from nuclear fallout and every nuclear bomb shelter that is being built is able to store lots of provisions that are needed so that people inside the nuclear bomb shelter can survive for months without every coming out of the bomb shelter. Get interesting information here: https://en.wikipedia.org/wiki/Bomb_shelter.