  We extend a previous numerical study of SU(3) Yang-Mills theory in which we
measured the spatial distribution of all components of the color fields
surrounding a static quark-antiquark pair for a wide range of quark-antiquark
separations, and provided evidence that the simulated gauge invariant
chromoelectric field can be separated into a Coulomb-like 'perturbative' field
and a 'non-perturbative' field, identified as the confining part of the SU(3)
flux tube field. In this paper we hypothesize that the fluctuating color fields
not measured in our simulations do not contribute to the string tension. Under
this assumption the string tension is determined by the color fields we
measure, which form a tensor $F_{\mu \nu}$ pointing in a single direction in
color space. We call this the Maxwell mechanism of confinement. We provide an
additional procedure to isolate the non-perturbative (confining) field. We then
extract the string tension from a stress energy-momentum tensor $T_{\mu \nu}$
having the Maxwell form, constructed from the non-perturbative part of the
tensor $F_{\mu \nu}$ obtained from our simulations. To test our hypothesis we
calculate the string tension from our simulations of the color fields for ten
values of the quark-antiquark separation ranging from 0.37 fm to 1.2 fm. We
also calculate the spatial distributions of the energy-momentum tensor $T_{\mu
\nu}$ surrounding static quarks for this range of separations, and we compare
these distributions with those obtained from direct simulations of the
energy-momentum tensor in SU(3) Yang-Mills theory.
