[en] The suppression of the isospin-1/2, three-body photodisintegration of ³He is shown to result from two facts: (1) For the S = 1/2, I = 1/2 states of three nucleons, the spin-isospin symmetries lead to integral equations dominated by a single effective interaction V⁺, which is the average of the NN s-wave spin-singlet and spin-triplet interactions and (2) This V⁺ supports a bound state due to the nature of the NN effective-range parameters. In the approximation that the (1/2,1/2) states are generated from V⁺ alone, it is clear that a fraction of the isospin-1/2 bremsstrahlung-weighted sum rule must come from two-body photodisintegration with a corresponding reduction of the three-body channel contribution, since the total isospin-1/2 sum rule is fixed. The substantial reduction of the actual physical isospin-1/2, three-body photodisintegration is directly related to the strength of V⁺