Why might this parade of military equipment have taken place

A military parade is formation of alot of soldiers whose movement is restricted by close order drilling The military parade is now almost entirely ceremonial, though soldiers from time immemorial up until the late 19th century fought in formation. Massed parades may also hold a role for propaganda purposes, being used to exhibit the apparent military strength of one's nation.

social contract theory basically says that all individuals are born equal, and provided a god given right to consent to be governed. american government is based of this

thomas hobbes and john locke said that we are selfish, individualistic, and constantly at war with each other, therefore we need to be controlled. 

government is defined as the legitimate use of force to control human behavior within territorial boundaries, here comes in hobbes and locke.

hobbes takes the part about controlling human behavior. while locke takes the part of legitimate use of force, since force is not legitimate unless there is consent of the people. 

there are basically 3 goals of the government: 1) maintain order by protecting life and property. 2) providing public goods, those which are typically not provided by the public sector, such as roads and education. 3) promote equality be it political, opportunist or outcome equality.