  Yang-Mills theory is studied in a variant of 't Hooft's maximal Abelian
gauge. In this gauge magnetic monopoles arise in the Abelian magnetic field. We
show, however, that the full (non-Abelian) magnetic field does not possess any
monopoles, but rather strings of magnetic fluxes. We argue that these strings
are the relevant infrared degrees of freedom. The properties of the magnetic
strings which arise from a dilute instanton gas are investigated for the gauge
group SU(2).
