  We study the breakup of a liquid jet a few nanometers in diameter, based on a
stochastic differential equation derived recently by Moseler and Landman
[Science {\bf 289}, 1165 (2000)]. In agreement with their simulations, we
confirm that noise qualitatively changes the characteristics of breakup,
leading to symmetric profiles. Using the path integral description, we find a
self-similar profile that describes the most probable breakup mode. As
illustrated by a simple physical argument, noise is the driving force behind
pinching, speeding up the breakup to make surface tension irrelevant.
