Which condition made the western roman empire vulnerable to attack?

I believe the answer is: Splitting of empire; Weak borders

The splitting empire happened because of the power struggle among the kings' Sons. The split resulted in the reduction of Roman military power which made them become weaker compared to other empires. Weak border provide opportunities for Barbarian tribes to come in an raid Roman villages.

haitian revolution slaves initiated the rebellion in 1791 and by 1803 they had succeeded in ending not just slavery but french control over the colony

abraham lincoln