  Monte Carlo simulations are performed in a five-dimensional lattice SU(2)
Yang-Mills theory with a compactified extra dimension, and scaling laws are
studied. Our simulations indicate that as the compactification radius $R$
decreases, the confining phase spreads more and more to the weak coupling
regime, and the effective dimension of the theory changes gradually from five
to four. Our simulations also indicate that the limit $a_4 to 0$ with $R/a_4$
kept fixed exists both in the confining and deconfining phases if $R/a_4$ is
small enough, where $a_4$ is the lattice spacing in the four-dimensional
direction. We argue that the color degrees of freedom in QCD are confined only
for $R < R_{\rm max}$, where a rough estimate shows that $1/R_{\rm max}$ lies
in the TeV range. Comments on deconstructing extra dimensions are given.
