  Excitation energies of the $T$=1 states in even-even as well as $T$=0 and
$T$=1 states in odd-odd $N$=$Z$ nuclei are calculated within the mean-field
approach. It is shown that the underlying structure of these states can be
determined in a consistent manner only when both isoscalar and isovector
pairing collectivity as well as isospin projection, treated within the
iso-cranking approximation, are taken into account. In particular, in odd-odd
$N$=$Z$ nuclei, the interplay between quasiparticle excitations (relevant for
the case of $T$=0 states) and iso-rotations (relevant for the case of $T$=1
states) explains the near-degeneracy of these fundamental excitations.
