  Short distance static quark--antiquark interaction is studied systematically
using the background perturbation theory with nonperturbative background
described by field correlators. A universal linear term
$\frac{6N_c\alpha_s\sigma r}{2\pi}$ is observed at small distance $r$ due to
the interference between perturbative and nonperturbative contributions.
Possible modifications of this term due to additional subleading terms are
discussed and implications for systematic corrections to OPE are formulated.
