The key differences here between this historically validated theory and the "way out on left field" notion of "permanent revolution" are:
1) The need to
ally and not merely
lean on the peasantry (Trotsky regarded them as second-class citizens
) and other petit-bourgeois elements (while excluding the bourgeoisie); and
2) The recognition that capitalism as a historical stage CANNOT be skipped (and hence the implicit recognition that a second
social revolution in the distant future is needed, no matter how many "socialist tasks" - mostly political and not economic - can be accommodated in the period following the social-democratic revolution).