  Assuming that the recent result obtained from the Monte Carlo simulations on
the nonperturbative existence of the pure SU(2) Yang-Mills theory in five
dimensions can be applied to a more general class of higher-dimensional gauge
theories, we derive the conditions imposed by the nontriviality requirement on
the theories. We find that the supersymmetric grand unified theories with extra
dimensions prefer a large value ($\gsim 2$) of $\tan\beta$ of the minimal
supersymmetric standard model, in accord with today's possible observation of
the Higgs particle at LEP2.
