  We show that gluodynamics in an external Abelian electromagnetic field should
possess a deconfining phase transition at zero temperature. Our analytical
estimation of the critical external field is based on the dual superconductor
picture which is formulated in the Euclidean space suitable for lattice
calculations. A dual superconductor model corresponding to the SU(2)
gluodynamics possesses confinement and deconfinement phases below and,
respectively, above the critical field. A dual superconductor model for the
SU(3) gauge theory predicts a rich phase structure containing confinement,
asymmetric confinement and deconfinement phases. The quark bound states in
these phases are analyzed. Inside the baryon the strings are Y--shaped as
predicted by the dual superconductor picture. This shape is geometrically
asymmetric in the asymmetric confinement phases. The results of the paper can
be used to check the dual superconductor mechanism in gluodynamics.
