Problem ofαsin supersymmetric unified theories

It is shown that in $\mathrm{SO}\left(10\right)\mathrm{}$ there is a general connection between the suppression of Higgsino mediated proton decay and the value of ${\alpha }_s.$ However, agreement with the experimental value of ${\alpha }_s$ can be obtained if there are relatively large negative threshold corrections to ${\alpha }_s$ coming from superheavy split multiplets. It is shown that such split multiplets can arise in $\mathrm{SO}\left(10\right)\mathrm{}$ without fine-tuning of parameters.