  We investigate tunneling through a short interacting wire. We identify two
temperature regimes (a) $T_{Kondo}<T\le T^{wire}=\hbar v_F/k_Bd$ ($d$ is the
length of the short wire) and (b) $T<T_{Kondo}\ll T^{wire}$. In the first
regime the effective (renormalized) electron-electron interaction is smaller
than the tunneling matrix element. This is the situation at finite temperature
$T$ where the single particle spectrum of the wire is characterized by a
multilevel "quantum dot" system with magnetic quantum number S=0 which is
higher in energy than the SU(2) spin doublet $S=\pm1/2$. Due to the single
particle energy we find that the tunneling electron into the wire must have an
opposite spin to the one in the short wire giving rise to a conductance, $G=
G_\uparrow+G_\downarrow$, $e^2/h\le G\ll 2e^2/h$. In the second regime, when $T
\to0$ we have a situation that the effective (renormalized) electron-electron
interaction is larger than the tunneling matrix element. This problem is
equivalent to a Kondo problem. We find for $T<T_{Kondo}$ that the conductance
is given by $G=2e^2/h$. These results are in agreement with recent experiments
where for $T_{Kondo}<T<T^{wire}$ the conductance $G$ obeys $e^2/h\le G\ll
2e^2/h$, and for $T< T_{Kondo}$, $G=2e^2/h$. In both regimes the current is not
polarized and the SU(2) symmetry is not broken.
