Rare Kaon and Pion Decays: Incisive Probes for New Physics Beyond the Standard Model

We review the current status and future prospects of rare kaon and pion decay research programs. Our emphasis is on experimental probes of New Physics beyond the Standard Model via the theoretically pristine decays and precision tests of electron-muon universality. These studies test the Standard Model at the level of its quantum-loop predictions and have the potential to uncover new interactions beyond the O(1,000 TeV) scale.