Let's imagine a situation: one day without any preconditions Earth was attacked by unknown beings. They do not have firearms, but they have a sharp and durable blades. They walk pretty slow and have poor eyesight. Their size and weight approximately correspond to the average person. The number corresponds to the number of people around.
They appear out of nowhere - teleported directly on the surface of the planet, in all points where there is nothing to prevent them from freely stand - on city streets, inside homes, shelters, bank vaults, on the roofs of the buildings. After the appearance they attack people, break everything that comes their way, especially high-tech stuff. Aliens do not spare anyone or anything. They particularly focused on hi-tech and attack people only if they are too close or attacking them first. They show no signs of intelligence. They act mostly unconsciously.
They seek not to kill people but to destroy the high-tech stuff. If people decide to escape - they will not pursue them. The number of attackers is always roughly equal to the number of people around - in densely populated areas will be a lot of aliens, in sparsely populated - a few, where there are no people - and no aliens. The choice of teleportation point is completely random - they may appear far away from the people, and may be close, but never close enough be forced to attack immediately (therefore rarely appear inside the houses where the people are present).
As not intelligence creatures they are trying to destroy the tech, because experiencing some unpleasant sensation from it. So they attack in the first place that exudes the most "technical" effect. Nobody knows what exactly feel alien - electromagnetic fields, radiation or vibration, but they attacks in mainly the most complex and large-scale technical objects.
And an hour later they disappear as quickly as it appeared, along with the bodies of dead aliens. After a few days the situation repeats, and will continue to be repeated once every few days (period not constant and varies between 3-5 days). The world is almost apocalyptic.
Aliens do not care about how much of them die during this attacks, and almost do not have the instinct of self-preservation. The number of aliens that take part in the next attack always will be approximately equal to the number of people in a particular area. Attacks in different parts of the World happen mostly daytime.
Q: What long-term changes occur in society, government, army and religion while there is a constant periodic threat? Whether the army can effectively resist the new enemy that appears in the middle of military bases, inside the barracks and staffs? Do people become more evil in an environment where no one monitors compliance of the law? Which of the life support systems and social benefits will be broken? (power supply, water supply, production of food, etc.)
P.S. I am afraid that the question can be counted as too broad. If so, I'll try to narrow it down to just the question about a society.