  The future lepton colliders proposed for the High Energy and Precision
Frontier set stringent demands on theory. The most ambitious, broad-reaching
and demanding project is the FCC-ee. We consider here the present status and
requirements on precision calculations, possible ways forward and novel
methods, to match the experimental accuracies expected at the FCC-ee. We
conclude that the challenge can be tackled by a distributed collaborative
effort in academic institutions around the world, provided sufficient support,
which is estimated to about 500 man-years over the next 20 years.
