A surface forces apparatus and various optical visualization techniques were used to study the transition mechanisms between liquid-like snapping and solid-like failure at nano- and microscales. Transient deformations and flows of polymer necks were Studied over a large range of pulling forces, pulling rates, temperatures, and viscosities. A continuous transition is suggested-from simple neck-thinning and snapping, through viscous Fingering, to sharp solid-like cracking-between these two limiting modes of failure if one chooses to vary the system properties and experimental conditions in a systematic way. The Saffman-Taylor fingering equation Was found to remain valid down to nanoscopic dimensions, and a modified version Of it is Suggested to be suitable to elastic, solid-like materials.