There seems to be a lot of confusion with the Devs about this entire "combined arms" thing, as evidenced by the recent PTS changes. This thread is meant to explain what combined arms is historically, what it is in a modern 21st century context, why the "combined arms initiative" actually destroys any concept of combined arms, and what the "combined arms initiative" should be. To begin with, combined arms is the general concept that different unit types are more effective when used together than when used separately. That's all there is to it. In early warfare combat was dominated by simple foot infantry, so combined arms was fairly limited. Sure, you have archers/slingers and more melee oriented infantry, and their joint operations is probably the earliest ancestor to modern combined arms. You also had some of this with the introduction of pole arms. Nonetheless, this could not be correctly called combined arms as we know it today. The introduction of the mounted cavalry was a more significant change, because cavalry operated quite differently than foot infantry. Even then, the fighting tactics were not very sophisticated, both from a lack of military science and from poor training. For example, the Battle of Hastings in 1066CE featured archers, infantry, and cavalry, but each operated in a distinct and specific phase. First the archers would shoot, then the infantry would attack, and finally the cavalry would charge and break through weak spots in the line. That isn't true combined arms as we think of it today, where different units take part in combat simultaneously. After cavalry, field artillery was the next most important feature, taking a bit of the role of ranged archers. By the 18th century, infantry had been armed with firearms instead of their bows, spears, or swords. Cavalry had access to some firearms but largely remained melee. Artillery, however, allowed for the delivery of massive firepower to disrupt and destroy enemy formations. In the 1805 Battle of Austerlitz, artillery was used to great effect, especially canister shot against enemy infantry formations. Cavalry and infantry worked more closely together, though still in separate formations. The Great War in 1914 was the beginnings of what we view today as combined arms. Artillery-infantry coordination was the first to come, with infantry assaulting behind a "creeping barrage" of artillery shells. In this way, artillery greatly enhanced (in theory) the effectiveness of infantry. Armour also made its appearance in WWI (along with the effective death of the horse cavalry unit). While at first tanks were not used in a combined arms manner, usually assaulting enemy positions on their own, it was quickly discovered that tanks needed infantry support to consolidate and hold the land that the tanks had conquered. Tanks increased infantry effectiveness by being sources of fire support and protection, while infantry could guard the rear and flanks of early tanks. Besides armour, military aviation became more prominent at this time, though again generally did not operate closely with ground forces. The Second World War in 1939 showed the true power of combined arms. The Germans began the conflict with a fairly innocent weapon: the tank-mounted radio. Unlike with Allied forces, all German armoured units were equipped with a radio, which allowed them to call in artillery and air support or to direct infantry to threats. This made up for the fact that German tanks at the beginning of the war were actually inferior in terms of quality and quantity. It also showed the power of true combined arms, that a much smaller and technically weaker force could overcome the enemy when the strength of each tank, aircraft, artillerypiece, or infantryman was increased because they were used together. German combined arms quickly became the model to follow for all armies that could. The end of the World Wars marked a transition to an end to "great power" wars fought between near-peer countries. Instead, much of warfare after the Korean War turned to unequal conflicts or low-intensity operations. Only a few instances like the Israeli or Pakistani-Indian conflicts featured conventional armies locked in combat. Even in these conditions, however, combined arms became the preferred method of combat for those who could afford it, whether in tropical or desert environs.