A guy on my Facebook page broke it down like this. Racism (or in this case war) is about men competing with each other over recources. Women for the most part are shielded from this and enjoy whatever spoils of war their men get.

Tiny penis syndrome

I honestly have no idea.

you really take an honest look at what our society/humans value. testostetone driven dominance, wealth, superiority, war, greed and selfishness dominate. The easiest way to understand human behavior is to study animal behavior. Humans are far from being civilized . we only give positive lip service to the more feminine attributes.

Testosterone and physical strength first. Then social gender roles. It is only complicated if you think men and women are equal.

Intra-species violence is virtually universal among mammals. If you want to understand why male humans exhibit it more than females you would have to look at the biochemical differences between the two genders, specifically hormone levels such as testosterone, and how they relate to reproductive advantage.
Arguments from psychology or sociology are generally circular or vapid but they make good fillers if you're going to press with a newspaper or magazine and don't have enough copy.

If you look at the overall history men have been raised to be the aggressor. They have been the hunters and warriors. It has only been a very short time that civilization has exisisted. When you consider the amount of time to make a change in nature, man is actually changing far faster than the norm. Could have something to do with the fact humans don't have instincts. For the most part I think it is a learned response. Society still applauds that kind of behaviour in men. The military does not look for women to go into battle. Most movies, games etc.. about violence is marketed to men. When you hear "chick flick", what do you think of, I don't think violent film came to mind. When someone says they're going to do something manly or going to watch a manly movie, what comes to mind. It is imposed on a man and unless a specific man makes a conscious decision to change, they will fall into that mind set.

Women After All by Melvin Konner, MD should have some useful insights for you there.

It's something I have pondered for decades. For the most part gender differences are trivial, males and females are essentially the same. Yet when it comes to physical violence, males are wildly overrepresented. Needs more study I guess.

I think it's related to man's obsessive pursuit of power and control and societies general acceptance and admiration of it. Power is sold as attractive and attraction is what ensures reproduction. Once it becomes unattractive to "rule" maybe things will change. And WOMEN ultimately decide what is attractive in men so the power to change it is within us!

Because of a stupid tradition in education. I suffered from it to the point that I was hoping never to have sons.For starters I had two elder brothers, went to an all boys high school and was drafted into a all male navy.

I believe that the right (or wrong) levels of testosterone (i.e. Too much) at just the wrong stage of growth and development can cause the amygdale to develop improperly.   Improperly developed amigdales  cause psychosis.  Males are more likely to experience this for obvious reasons having to do with their hormone production cycle.

One of many reasons I think is religion; (written by man (male)) places superior power and worth over women in the hands of male.

Maybe because males have all (or most) of the power? Also, I know that I could never be a soldier/warrior because I am a giver of life. I could not take a life of someone's (grown up) child. Not all people feel the same, and that is good. I am caring and loving...someone has to be strong enough to protect people like me.

Power and greed drive the beast. It is the male that seems to dominate this field more. whether due to Testosterone, environment, or both I don't know. But it takes just one person to spark rebellion in the many and led them on his or her crusade to victory. And it takes just 10% of the total population to control the 90% through cruel and extreme violence. And it takes a great deal of abuse to cause a reaction that may culminate in another leader to rally a rebellion strong enough and devastating enough to overthrow the previous one.
And this new leader will have to have the drive and will to win or die no matter the cost. So, it is hard to reign in the new leader to share in a democratic way. The cycle of violence is embedded in our DNA and takes a great society and shared vision to bring about a democratic society. And it takes a populous that is enlightened and educated to hold it together. Our society today is under attack constantly by others who want power and have the resources to control much of what happens. If only women were in power they would have to be on some level the same as the men in order to hold that power. Would that change things for better or worse? No one knows that for sure. Only speculation.

It is mostly a matter of opportunity, given the chance all humans are capable of horrific actions if they are that way inclined.
Men do not like this to be made widely known, because they do not want women "getting uppity" and knowing they are capable of fighting back or of terrifying men.
For example the first SS officer sentenced to death for war crime atrocities while in command of the women's section of the Nazi concentration camps of Ravensbrück, Auschwitz, and Bergen-Belsen was named Irma Ida Ilse Grese, ever heard of her?
No because everyone remembers Mengler, Himmler and the ilk, nasty little cruel men, but the idea that the most prolific monster of the concentration camps was a young woman is too dangerous an idea to be proliferated.
Even the military genius and ruthless soldier Joan of Arc, is better remembered for having been burned to death as punishment than for her victories and massacres. Even in her own time she was not executed for war crimes but for the biblically legislated crime of Transvestisms.

My point is that men and women are equally capable of horrendous behaviour, but the crimes of women are reported less frequently and in less graphic detail, because the myth and expectations of femine behaviour has been a great tool in actually repressing women.
Ask any one who grew up with a sister, or an abusive mother, or was unfortunate enough to be a battered husband, just how vicious and cruel a woman can be given the opportunity and inclination to do so.
The myth once established is passed from mother to daughter like an herditory condition.

I just thinkmen are more aggressive. You have to think what it might have been like if there were more women with more power in the 3rd Reich. Speaking of which, there is a sad lack of womens influence with the White House today.

Dehumanization of the enemy enables one side of a conflict to see the other side as non human, as "heathen" "godless" "subhuman" "Demonic" and so forth.
This is the exact same psychological mechanism which comes into play in kidnap scenarios, the criminal dehumanizes the victim until they are "not human" but a thing, to which they few inhibitions. This Psychological Mechanism becomes sociologically driven, both by the overall society (seeking revenge), by the Language adopting terms to lessen the other (Nip, Raghead, Charlie, ect), and by the repitition of stories of loss on each side. Each side retells their 9-11 tales to restoke hatred.

All that boils into a soup which results in what you find in war zones.

In the beginning humans lived in caves. They had biological drives so men and women would cohabit.
One Ugg's wife Ogg said to Ugg "Trog's cave is bigger than ours, safer, drier, easier to keep warm and closer to the springwater. I want to live like that".
Well that was the only other cave on the block and Ogg started developing "not in the moods" and "headaches" to make sure that Ugg got the message. So totally frustrated and driven on by Ogg's complaining poor Ugg had to take his cudgel and beat his good neighbour Trogg, Trogg's wife and his children to death.

And that children is how the first murder and theft occurred.
How the first elephant got into the room.
How women protect their thinking by projecting their actions onto others, particularly men.
How man got blamed by misandrists for all the ills of the world.

So @Waterbaby you cannot see the Syrian elephant in the room aka Exxon wanting to maintain yours and the American lifestyle by stealing cheap oil at the expense of the rest of the world?

Most cultures are still male dominated with females as submissive. That alone probably addresses the question.

I for one, wish to see women leading all nations on the planet Women have much more compassion and logic than a man in a man's world Women will soon be the nuturing agent we are looking for in leadership

As long as Homo Sapiens has walked the earth, the male has been the more dominant and aggressive sex. Men were the hunters, women, the gatherers. As a result of the Agricultural Revolution, the natural male aggression, competitiveness and dominance have been channeled into other, less productive avenues, and so atrocious behavior of the male has become more prevalent. With agriculture came settlements, thus the concept of private property, which then led to the advent of wars.....in other words, “let the atrocities begin!” And, of course, Religion was developed in order to control human behavior. How has THAT worked out for us?

I believe that this is a tendency that goes back to cave men. We are all tribes. From the beginning mankind has identified "others." Men were the hunters, protectors, the killers. Like all other animals testosterone and the need to identify "other's" has caused death for thusands of years. I agree with MrHIT

Mankind at is worse beahviour

I think THIS book will be a good read! "Things That Make White People Uncomfortable": Michael Bennett's Essential New Book

'Finally, Things That Make White People Uncomfortable will teach you that it's okay to ask the biggest questions about how our world is organized. Michael writes about his trip to Haiti with his Haitian teammate Cliff Avril and says, "It reminded me of being young and asking my mother, "Why?" As in, Why does the world even have to be like this? If you don't ask why you'll never be attacked or criticized. No one is going to go after you or your family. But if you don't ask why, nothing, not a damn thing, is ever going to change."'

[truth-out.org]