  Quasar-driven galactic outflows are a major driver of the evolution of
massive galaxies. We report observations of a powerful galactic-scale outflow
in a $z=3$ extremely red, intrinsically luminous ($L_{\rm bol}\simeq 5\times
10^{47}$erg s$^{-1}$) quasar SDSSJ1652+1728 with the Near Infrared Spectrograph
(NIRSpec) on board JWST. We analyze the kinematics of rest-frame optical
emission lines and identify the quasar-driven outflow extending out to $\sim
10$ kpc from the quasar with a velocity offset of ($v_{r}=\pm 500$ km s$^{-1}$)
and high velocity dispersion (FWHM$=700-2400$ km s$^{-1}$). Due to JWST's
unprecedented surface brightness sensitivity in the near-infrared -- we
unambiguously show that the powerful high velocity outflow in an extremely red
quasar (ERQ) encompasses a large swath of the host galaxy's interstellar medium
(ISM). Using the kinematics and dynamics of optical emission lines, we estimate
the mass outflow rate -- in the warm ionized phase alone -- to be at least
$2300\pm1400$ $M_{\odot}$ yr$^{-1}$. We measure a momentum flux ratio between
the outflow and the quasar accretion disk of $\sim$1 on kpc scale, indicating
that the outflow was likely driven in a relatively high ($>10^{23}$cm$^{-2}$)
column density environment through radiation pressure on dust grains. We find a
coupling efficiency between the bolometric luminosity of the quasar and the
outflow of 0.1$\%$, matching the theoretical prediction of the minimum coupling
efficiency necessary for negative quasar feedback. The outflow has sufficient
energetics to drive the observed turbulence seen in shocked regions of the
quasar host galaxy, likely directly responsible for prolonging the time it
takes for gas to cool efficiently.
