Why am I getting SQLite3::ConstraintException: foreign key constraint failed?

Here's how I'm inserting in the database.

Tagged.insert(:user_id => 1, :tag_id => 1, :debate_id => 9)

Here's my table structure

create_table(:tagged) do
      primary_key :id
      foreign_key :user_id, :users, :key => :id, :null => false
      foreign_key :tag_id, :tags, :key => :id, :null => false

      foreign_key :post_id, :posts, :key => :id
      foreign_key :debate_id, :debates, :key => :id
      foreign_key :group_id, :groups, :key => :id

      String :deleted, :default => 'no'

      String :datenumber, :null => false
      String :datetimenumber, :null => false
    end

Row number 9 on debates table exists.