There are a lot of special achievements in "Frost Age 2", and being attacked from both sides is one of them. To achieve this achievement, you only need to have a negative relationship with all communities and factions. This kind of thing is not difficult. Big, just do something a little more extreme.
How to achieve the achievement of being attacked from both sides in Ice Age 2
Being attacked from both sides
Negative relations with all communities and factions
Location: Story or Utopia Builder
This happened quite naturally while I was playing the story, and while I was trying to please everyone in the council, I managed to make them equally angry with me :D
Essentially, if you don't do it right, you piss everyone off
Deliberately behave badly, or repeatedly denounce each faction until they all riot.
Ways to anger factions:
Voting laws violate their beliefs
Research techniques that go against their beliefs
Make decisions in town or in Frostland, which may anger them
Condemn them - Select an avatar of any faction and choose Condemn (as shown)
Overall poor performance