The problem of the progressive collapse of structures is today at the forefront of structural engineering because of multiple natural and man-made hazards, the aging of the infrastructure and the catastrophic consequences associated with that. This paper investigates the effects of different strengthening techniques for mitigating the phenomenon of progressive collapse for 2D steel moment frames. These techniques are applied to a series of moment frames of varying heights and designs using a finite element analysis involving both material and geometric non-linearities. The results of this work demonstrate that, when analyzed as 2D assemblies, realistic, similar steel frame structures undergo different collapse mechanisms and that a general strengthening scheme cannot be applied to all collapse mechanisms.