  We use loop induced processes like meson oscillations and rare b hadron
decays to determine the absolute values of the CKM matrix elements $|V_{ub}|$
and $|V_{cb}|$ and compare our results to the standard determinations based on
inclusive and exclusive semileptonic tree-level decays of B mesons. For many
years there have been tensions between the inclusive and exclusive
determinations. Assuming the absence of new physics, we find that meson
oscillation data shows a slight preference for the inclusive value of
$|V_{cb}|$ and the exclusive value for $|V_{ub}|$. Rare b decay data prefers
values for $|V_{cb}|$ far below the inclusive and exclusive determinations,
offering a new perspective on some of the persistent rare b decay anomalies.
