  In this paper we prove the following abundance-type result: for any smooth
Fano variety $X$, the tangent bundle $T_X$ is nef if and only if it is big and
semiample in the sense that the tautological line bundle
$\mathscr{O}_{\mathbb{P}T_X}(1)$ is so, by which we establish a weak form of
the Campana-Peternell conjecture (Camapan-Peternell, 1991).
