  Utilizing a benchmark measurement of laser-induced ionization of an H$_2^+$
molecular ion beam target at infrared wavelength around 2 $\mu$m, we show that
the characteristic two-peak structure predicted for laser-induced enhanced
ionization of H$_2^+$ and diatomic molecules in general, is a phenomenon which
is confined to a small laser parameter space --- a Goldilocks Zone. Further, we
control the effect experimentally and measure its imprint on the electron
momentum. We replicate the behavior with simulations, which reproduce the
measured kinetic-energy release as well as the correlated-electron spectra.
Based on this, a model, which both maps out the Goldilocks Zone and illustrates
why enhanced ionization has proven so elusive in H$_2^+$, is derived.
