The Mesopotamian Civilization had a surprisingly adept grasp of tactics. In fact, they are the first confirmed users of the shield wall tactic later made famous as the Roman "testudo formation". It is unknown who first developed this tactic, but it is thought to have been developed somewhere between 2500 BC and 2000 BC.
Another Mesopotamian tactic involved small, well-disciplined (for the time) spearman formations. Armed with javelins, they were the first effective missile troops, as shown during their war against the Hittites in around 2000 BC. These missile units were later idealized in the famous epic poem "The Sie." The Mesopotamian battle formation consisted of the shield wall and short-sword armed sliders in front, and the missile troops behind, with charioteers on the flanks. These formations served the Mesopotamians well for many years, but were eventually outclassed by slingers and archers.
In each race that thrived in Mesopotamia, military and defensive tactics differ. The Sumerians invented the horse-drawn chariot with lighter wheels, allowing quick maneuvering and evasion in the battlefield. Akkadians and Babylonians focused on their military power because of constant threats from neighboring tribes and kingdoms. Amidst all this, however, the Assyrians were one of the most successful military kingdoms. They were one of the first to produce iron weapons, which became essential to every army.