​If deterrence fails and diplomacy falters, how can small states defend themselves against adversaries that outnumber, outgun and outmatch them? This study seeks to contribute to the ongoing scholarly discourse on how "the few" can achieve a military upset - not just a political or a propaganda one- against "the many." In an era where asymmetric war has become the most anticipated type, understanding the innovative ways of warfare that enable the smaller forces to endure and even prevail is of paramount importance to strategic analysts, military commanders, and policymakers alike. To do so, the study coins a definition for the concept of "Hybrid Defence," contributes a new definition of "Multi-Domain Combined Arms Operations" and examines their correlations with, and impacts on, "Military Effectiveness" and "Combat Effectiveness." It then analyses selected operational arts and tactical adaptations employed by the relatively smaller forces - such as the Ukrainian Military and Security Forces, as well as nonstate forces, exemplified by the Palestinian Resistance Factions in Gaza - for confronting numerically and technologically superior adversaries. The study extracts seven key lessons and concludes with their comparative implications for the defence policies of small states, particularly in the Arab world and beyond.