  The ancient problem of the saturation of symmetric nuclear matter is reviewed
with an update on the status of the crises that were identified at an early
stage by John Clark. We discuss how the initial problem with variational
calculations providing more binding than the two hole-line contribution for the
same interaction was overcome by calculations including three hole-line
contributions without however reproducing the empirical nuclear saturation
properties. It is argued that this remaining problem is still open because many
solutions have been proposed or ad hoc adjustments implemented without
generating universal agreement on the proper interpretation of the physics. The
problem of nuclear saturation therefore persists leading to the necessity of an
analysis of the way the nuclear saturation properties are obtained from
experimental data. We clarify the role of short-range correlations and review
results for nuclear saturation when such ingredients are completely taken into
account using the Green's function method. The role of long-range correlations
is then analyzed with special emphasis on the importance of attractive
pion-dominated excitation modes which inevitably lead to higher saturation
densities than observed. Because such modes have no counterpart in finite
nuclear systems, it is therefore argued that they should not be considered when
calculating nuclear matter properties. The remaining open question is then
whether long-range correlations in finite nuclei which in turn have no
counterpart in infinite matter, represent the remaining missing ingredient in
this analysis.
