  We study vacuum dynamics of SU(3) lattice gauge theory at finite temperature
using the lattice Schr\"odinger functional. The SU(3) vacuum is probed by means
of an external constant Abelian chromomagnetic field. We find that by
increasing the strength of the applied external field the deconfinement
temperature decreases towards zero. This means that strong enough Abelian
chromomagnetic fields destroy confinement of color. We discuss some
consequences of this phenomenon on confinement and quark stars.
