  The possibility that the Standard Model (SM) is valid up to the Planck scale
$M_P$, i.e. that new physics occurs only around $M_P$, is nowadays largely
explored. For a metastable EW vacuum, we show that new physics interactions can
have a great impact on its lifetime, and, differently from previous analyses,
they cannot be neglected. Therefore, contrary to usual believes, the stability
phase diagram of the SM depends on new physics. This has far reaching
consequences. Beyond SM theories can be tested against their prediction for the
stability of the EW vacuum. Moreover, despite of some recent claims, higher
precision measurements of the top and Higgs masses cannot provide any definite
answer on the SM stability properties. Finally, doubts on Higgs inflation
scenarios, all based on results obtained neglecting new physics interactions,
are also cast.
