c'mon crab, you can't be that unable to read with an open mind:
the Aerodynamic force on a blade acts at the Center of Pressure, if it is not co-incident with the Pitch Change Axis (almost the same thing as the Longditudinal Axis of a Blade) this will result in a Torsional Force about this Axis, this force will have to be resolved by the Pitch Link (and thereby the control rods and hydraulics if there are any). The distance of the CoP from the Pitch Change Axis is the 'Arm' and the Magnitude does indeed depend on the Lift being generated. The force from this factor needing to be supplied by "Control Forces' (or Hydraulics) will be the product of Magnitude and Arm.
The second force that Controls (or Hydraulics) need to supply is the Force required to change the pitch every revoloution.
One variable that both factors are dependant on is the Chord.
OK? If not re-read. (althought the Boulleux jape is irresistible.)