An analysis of the structure and thermodynamics of the spherical liquid-vapor interface of a simple fluid confined to a finite volume is presented. Numerical solutions of the Yvon-Born-Green equation for the singlet density distribution of a Lennard-Jones fluid are obtained, tested by comparison with recent molecular dynamics results, and then used to compute radially dependent surface tensions and surfaces of tension from mechanical expressions for these properties. These results and molecular dynamics temperature quenching experiments are used in an analysis of assumptions upon which the classical theory of homogeneous nucleation from a metastable vapor is based. The significance of interfacial free energy contributions in the early growth stage is found to be overstated. Cluster-cluster interactions are shown to play a dominant role in the nucleation process.