be at the bottom of something

be at the bottom of (something)

To be the fundamental cause of something. Stubbornness is at the bottom of every unresolved disagreement.
See also: bottom, of
Farlex Dictionary of Idioms.

be at the bottom of something

If something is at the bottom of a situation, it is the real cause of it. Remember that pride is at the bottom of all great mistakes. Note: You can also say that something lies at the bottom of a situation. This decision quite probably lies at the bottom of the colony's current discontent.
See also: bottom, of, something
Collins COBUILD Idioms Dictionary, 3rd ed.

be/lie at the ˈbottom of something

be the basic cause of something: Racist feelings almost certainly lie at the bottom of these recent attacks.
See also: bottom, lie, of, something
Farlex Partner Idioms Dictionary
See also:
  • be at the bottom of (something)
  • lie at the bottom of (something)
  • be/lie at the bottom of something
  • at bottom
  • at the bottom of the hour
  • the bottom of the hour
  • from the bottom of (one's) heart
  • from the bottom of heart
  • from the bottom of my heart
  • from the bottom of your heart