Reddit reviews The Rise and Decline of Nations: Economic Growth, Stagflation, and Social Rigidities

Political scientist Mancur Olson described and formalized this problem in his 1984 book The Rise and Decline of Nations.

This is a pretty good explanation

In addition, as govts grow larger they get spread thinner and as a result anything that is contributed by the individual does not see a tangiable marginal benefit in the long run. Even economist Mancur Olsen's (not a libertarian or anarchist in the least) Rise and Decline of nations explains collective action and its poor outcomes when scaled.

If you want more examples there are more than enough sources out there to credit.

That's exactly what I had in mind. After reading Muncur Olsen the world makes a lot more sense.

Enjoy the decline!

Could you please rephrase your question in the form an Edwin Starr song? :)

1. War can provide huge spoils to the winners. (But this is not always true.)
   
   
2. War can be good for surviving males. Since war deaths are disproportionately male, war can ease the competition for females. This is especially beneficial in countries in which males already outnumber females. China is such a country, which inspired this Forbes article.
   
   
3. Similarly, the deaths of many males can be good for the broader population. This is because having a lot of males with time on their hands can lead to large problems. As the Forbes article mentioned above notes, "An entire class of potentially angry, frustrated, relatively poor and uneducated single men can mean serious threats to societal stability, if this group builds a class identity that feels antagonized by society as a whole." (In addition to demographic trends such as China's, polygamy can also lead to a lot of mateless males. I've read that this can lead to instability, violence, and even war; I can't recall where I read that, though, and all I can find is this 2007 piece.)
   
   
4. According to Mancur Olson, the pioneering theorist of collective action, war can destroy the morass of rent-seeking that seems to exist alongside every government. As The Economist said in its 1998 obituary of Olson, "In any human society, he said, parochial cartels and lobbies tend to accumulate over time, until they begin to sap a country's economic vitality. A war or some other catastrophe sweeps away the choking undergrowth of pressure groups." The relevant book is The Decline and Fall of Nations.
   
   
5. Similarly, fighting a war against evil can lead to the evil side losing, which is an upside to fighting. (Caveats apply!)
   
   So war does, or can, have benefits, and some of them can be big. But in my opinion wars in the real world are almost never worth the costs.
   
   Edit: Added polygamy bit.

According to economist Mancur Olson societies stagnate as elites gain control over the state and use it to enrich themselves.

Since Germany and Japan had their power elites wiped away, their economies could restart without any such dead weight.

The Rise and Decline of Nations: Economic Growth, Stagflation, and Social Rigidities,