  The smallest integer t for which the Wilson loop W^{t} fails to exhibit area
law is known as the confinement index of a given field theory. The confinement
index provides us with subtle information on the vacuum properties of the
system. We study the behavior of the Wilson and 't Hooft loops and compute the
confinement index in a wide class of N=1 supersymmetric gauge theories. All
possible electric and magnetic screenings are taken into account. The results
found are consistent with the theta periodicity, and whenever such a check is
available, with the factorization property of Seiberg-Witten curves.
