  We compute the leading behaviour of the quark anti-quark potential from a
generalized Nambu-Goto action associated with a curved space-time having an
"extra dimension". The extra dimension can be the radial coordinate in the
AdS/CFT correspondence, the Liouville field in Polyakov's approach, or an
internal dimension in MQCD. In particular, we derive the condition for
confinement, and in the case it occurs we find the string tension and the
correction to the linear potential.
