What is the order of bond enthalpies of halogens? Why is it not opposite to that of bond lengths?

Explanation

Bond lengths of halogens are in the order :`F_(2) lt Cl_(2) lt Br_(2) lt I_(2)`.
But the experimental bond enthalpies are : `Cl_(2) gt Br_(2) gt F_(2) gt I_(2)`.
Bond enthalpy of `F_(2)` is very less, because lone pair - lone pair repulsions are appreciable in `F_(2)` as the bond length is small in `F_(2)`.
It was also thought, though not appropriate, that `F-F` bond is weak as multiple bond is not possible with no d-orbitals in the valence shell of fluorine.