Actions like rituals, rites and monuments are addressed to citizens. They are made to remember and to celebrate someone or something; and they allow people to face with the past. Indeed these form of memorial are useful for whom is alive and not for the victims.

The Unknown Soldier although it symbolize all dead soldiers, is mainly worthwhile to every wife, mother, relative or friend.  In every country there are differences between their Unknown Soldier, but they all have the purpose of unify citizens under the same ideal. In the specific a body for all body as a symbol of patriotism.

Monuments like the Unknown Soldier one are also useful for governments, indeed they present war as a required action to give stability and peace to all citizens.

So rituals, rites and monuments are symbolic action to make all citizens aware of their national story and identity. On the other hand they are expedient for politicians to excuse the massive sacrifice made by the citizens for their nation.