  We compare lattice data for the short-distance part of the static energy in
2+1 flavor quantum chromodynamics (QCD) with perturbative calculations, up to
next-to-next-to-next-to leading-logarithmic accuracy. We show that perturbation
theory describes very well the lattice data at short distances, and exploit
this fact to obtain a determination of the product of the lattice scale r_0
with the QCD scale Lambda_{MS}. With the input of the value of r_0, this
provides a determination of the strong coupling alpha_s at the typical distance
scale of the lattice data. We obtain alpha_s(1.5 GeV)=0.326\pm0.019, which
provides a novel determination of alpha_s at low energy and with three-loop
accuracy (including resummation of the leading ultrasoft logarithms). When this
value is evolved to the Z-mass scale M_Z, it corresponds to
alpha_s(M_Z)=0.1156^{+0.0021}_{-0.0022}.
