  The Dual QCD (DQCD) framework, based on the ideas of 't Hooft and Witten, and
developed by Bill Bardeen, Jean-Marc Gerard and myself in the 1980s is not QCD,
a theory of quarks and gluons, but a successful low energy approximation of it
when applied to $K\to\pi\pi$ decays and $K^0-\bar K^0$ mixing. After years of
silence, starting with 2014, this framework has been further developed in order
to improve the SM prediction for the ratio $\epsilon'/\epsilon$, the $\Delta
I=1/2$ rule and $\hat B_K$. Most importantly, this year it has been used for
the calculation of all $K\to\pi\pi$ hadronic matrix elements of BSM operators
which opened the road for the general study of $\epsilon'/\epsilon$ in the
context of the SM effective theory (SMEFT). This talk summarizes briefly the
past successes of this framework and discusses recent developments which lead
to a master formula for $\epsilon'/\epsilon$ valid in any extension of the SM.
This formula should facilitate the search for new physics responsible for the
$\epsilon'/\epsilon$ anomaly hinted by 2015 results from lattice QCD and DQCD.
