Answer:
The statement is a complete sentence.
Explanation:
The question is, do you need more information to understand what is said?
I think the sentence is just fine. You get the idea of what it means immediately.
For example if you had a sentence that said
Because I practiced throwing a curve ball, I struck the batter out.
and then you followed it with
Luck had nothing to do with it.
You should understand that I got the batter out, and luck had nothing to do with it.
Both authors of "In Flanders Fields" and "Dulce et Decorum Est!" chose the same historical event as the setting but these books shows the World War 1 from two absolutely different points of view. "In Flanders Fields" author praises and blesses all those warriors who protected their native land fighted for it and its future generations. While reading this story you feel persuasive tone that aimed to make you feel the same. "Dulce et Decorum Est!" shows the most appalling things that happened during the War and urges us that if we had ever been through It all it would have been the worst nightmare in our life. To conclude : in the first story author eulogizes War whereas the second warns against it.
It's summarizing when a passage is shortening by only focusing in the main points.