War is all father and the whole king

[Mural of War (1896), by Gari Melchers](By Mural artist is Gari Melchers (1862–1932). Photographed in 2007 by Carol Highsmith (1946–), who explicitly placed the photograph in the public domain. - Library of Congress, Prints & Photographs Division, LC-DIG-highsm-02247 (original digital file), uncompressed archival TIFF version (54 MB), Public Domain, Link)
According to Robert Glossop,
War is a large-scale conflict with the use of violence between organized groups that are governments or seek to establish governments. War is necessary to establish political power, that is, to establish laws and force the population to implement them.
"War is the phase of a conflict of societies in which organized organized mass violence or destruction is being waged by two or more political communities or coalitions of such communities."

[Ruins of Guernica (1937). The Spanish Civil War was one of Europe's bloodiest and most brutal civil wars.](By Bundesarchiv, Bild 183-H25224 / Unknown / CC-BY-SA 3.0, CC BY-SA 3.0 de, Link)
It does not seem strange that the goals of war are not happiness or the improvement of the well-being of ordinary people. All wars are in fact necessary to establish power over new communities of people, to subjugate and force them under their own rules of life. And all this does not happen at the expense of the government, but at the expense of us, ordinary people, who are not endowed with any power and who are giving their lives for this power. As the saying goes, "The Pani are fighting, while the slaves are shaking with the serfs."
Of course, the war has its own positive sides. It has always been believed that war is not only destructive properties, but also constructive, development-promoting states, especially for empires leading aggressive policy. The war affects virtually every aspect of the country's life. Mobilization activities of the country affect the economy, politics, science, technology, ecology and education. In this way, the war occupies, almost a central place in the development of the country.

[The Ottoman campaign for territorial expansion in Europe in 1566](By Lokman - Tarih-i Sultan Süleyman ("Zafarnâma"), History of Sultan Süleyman, Dublin, chester Beatty Library, MS 413, fol. 82a, Public Domain, Link)
Negative from military operations is, of course, violence, mutuality (both sides participate in the conflict), mass and destructiveness. Nothing passes without a trace. War is forever and will be kept in memory for a long time. Here simple sorry can not do.

Glossop R. "Nature of War"

The title of the word Heraclitus of Ephesus