Memorial Day in the U.S. dates as far back as our Civil War. It was called Decoration Day for the flags and floors placed on the headstones of those that died in service. There are some places where this is no longer done. There are cities that no longer hold parades or put out flags along their streets. To me, that is unfortunate.
I believe that no matter how you feel about individual wars or their outcomes it is important that a nation remember her dead soldiers and their surviving families. Frankly, I can think of nothing better to act as a deterrent to rash action than to be reminded of the price that is paid.