The reasons why it did start are not relevant. What is relevant is the scale of the slaughter.
Take a classroom, take only the boys, kill one on 4 and injure 3 on 4 and you have the WW1 for France.

I went in manoeuvre there as the Military Camps are in this area for the good reasons that nothing can be cultivate due to too much (sometime still active) heavy metal in the ground. There are still wires. You can still see the trenches.
And you have the soil. This white clay, which is white dust in summer and a white ice in winter. The continuous rains in autumn made any hole and paddle on this clay a cold sea that never disappears. It is a flat countryside so when the Northern wind picks up, you can’t escape from it. Frost and cold keep you awake even with modern military equipment, so in 1915… Only to stay in so miserable conditions would be a punishment, so to fight…
It was misery.

So, for me, the 11 of November are a humble Remembrance Day to the ones I didn’t listen when they were still alive. The ones who were gathered around the Monument aux Morts, and the list of Names written on it. This List was their friends, neighbours, brothers who suffered and died on various battles fields. The ones they went fishing in the Veyle when the sun plays on the waves of the water and the trees are singing in the wind, the ones they played then worked with in the fields and forests around the hameaux spread around the main village consisting in a Church, three pubs, a School, a Town hall, a boulangerie/grocery, a butcher and the blacksmith. Their village, my village.

And their flags: The reason why they were able to carry one was the fact they believed it was not in vain.
We can mock them and dismiss the reasons why they went through this. But they survive the peace because the little squares of silk were what was left to them.

The size and the Number of the Military Cemeteries are absolutely incredible. And they are not all in graves. There are still the Bones of the unidentified in the Ossuaire of Duaumont.
Millions of young individuals, their lives, dream and pity hopes erased. 1,300 men in a Company in the morning, 15 in the evening.