  Theory and numerical simulations of the Navier-Stokes equations are used to
unravel the inertia-driven dewetting dynamics of an ultrathin film of Newtonian
liquid deposited on a solid substrate. A classification of the film thinning
regimes at finite Ohnersorge numbers is provided, unifying previous findings.
We reveal that, for Ohnesorge numbers smaller than one, the final approach to
the rupture singularity close to the molecular scales is controlled by a
balance between liquid inertia and van der Waals forces leading to a
self-similar asymptotic regime with $h_{\text{min}} \propto \tau^{2/5}$, where
$h_{\text{min}}$ is the minimum film thickness and $\tau$ is the time remaining
before rupture. The flow exhibits a three-region structure comprising an
irrotational core delimited by a pair of boundary layers at the wall and at the
free surface. A potential-flow description of the irrotational core is
provided, which is asymptotically matched with the viscous layers, allowing us
to present a complete parameter-free asymptotic description of inertia-driven
film rupture.
