The Babylonian military campaign is marked by extraordinary cruelty. Unlike other empires that wage war to win the glory of victory, inherit new territories, or establish permanent governments, the Babylonians are driven by a uniquely destructive goal. From their highest leaders to the common people, the entire nation marches into battle solely to oppress, loot, and plunder [רש״י, מצודת ציון, אברבנאל]. Their ultimate purpose is nothing but total ruin [מצודת דוד, מלבי״ם, אברבנאל].
This intense drive is understood in different ways. Some describe it as a constant, burning desire and obsession for destruction [מצודת ציון, ביאור שטיינזלץ]. Others view it as a fierce, rapid gallop, where the invading horses and riders move with such speed that they appear to greedily swallow the ground before them as they advance [רש״י, אבן עזרא, מלבי״ם].
A geographic question arises regarding the direction of their invasion. Since Babylon is located to the east of the land of Israel, their conquest naturally moves westward. Why, then, are they described as facing east? One approach explains this as a metaphor. Their fierce expressions and destructive ambitions are compared to the east wind, known for being the harshest and most violent of winds [רש״י, רד״ק, אבן עזרא]. A related idea is that they are simply always facing forward, relentlessly pushing their campaign ahead [ביאור שטיינזלץ].
A second approach reads the eastward direction literally, revealing the tragic reality of their strategy. The invaders plan to gather their massive plunder and immediately turn back east to their homeland in Babylon. Because they have no intention of settling in the cities they conquer, they have no interest in preserving anything. They burn and destroy entire lands to the ground without a trace of mercy [מצודת דוד, מלבי״ם, אברבנאל]. As a result of this brutal style of conquest, they do not allow the defeated nations to remain in their homes. Instead, they gather masses of captives, as countless as the sand of the sea, and move on, leaving absolutely nothing behind [מצודת דוד, מלבי״ם, ביאור שטיינזלץ].