We argue that subduction of large, old oceanic basins versus small, young marginal basins should be more effective in involving and thus destroying passive continental margins. As a result, passive continental margins might be better preserved where subduction of small, young basins has occurred. We have discussed the implications of our hypotheses for the peri-Mediterranean Alpine belt. Using a published kinematic model, we estimated the sizes of the oceanic basins involved in the Alpine orogeny from the Dinarides to the Taurides-Pontides system. The tectonic consequences of these estimates bear on both the V-shaped termination of the Late Triassic Tethys Ocean to the west of the Dinarides and distinction between the Tethys (Vardar) basin to the northeast and the smaller and more complex intracontinental and/or marginal basins to the southwest. In accordance with our hypothesis, the margins of these southwestern basins have been better preserved than the passive margin of the Vardar oceanic basin, which has essentially disappeared.