War has destruction as its core aim. What sets it apart from other forms of violent confrontations between men or men and animal is its organised nature.

Even wars between primitive tribes happen as per some plan. Then there are ranks, roles assigned to ranks, and finally, men assigned to roles. Each role, a combat role, requires soldiers with unique skills0ji, potentially involving different weapons.
The resulting juggernaut is manipulated as a unit using a top-down command-and-control structure. An example:
It may be noted that each combat role requires one to use at least one type of weapon. A piece of weapon has traditionally been developed to kill a human being. Although we have developed some special weapons for oversized, gigantic animals like whales and elephants. But for our species, we have paid special attention! There have been far too many purpose-built weapons designed specifically to kill other humans efficiently.
The following chart gives a glimpse:
If you categorize weapon as hunting weapons and murder weapons, you get a chilling picture. We humans have been obsessed with murder. The sheer variety of murder weapons also points to an arms race across millennia!

A war is nothing but an organised, Sate-approved mass murder campaign.

The second interesting point about war is that it has been out and out of an all male game. Aggressors and defenders, the victorious and the vanquished, have always been men. Women's involvement has been marginal and mostly indirect.

Scientists started digging. Psychologists found women befriended strangers more easily. I always wondered how spontaneously they kissed and hugged other women upon meeting for the first time at social gatherings. Meanwhile, men just shook hands and smiled awkwardly.

Anthropologists have found that the tradition of shaking hands developed with the specific purpose of exposing the entire arm, showing that there was no hidden weapon! For the same reason, body language experts advise on keeping both the arms on the table with palms open.

Initially, I used to get intrigued by the Western habit of having meals with strangers or business contacts you got introduced to 5 minutes ago. Eating for an Asian is a private affair. How can that activity foster bonding and bonhomie?

The answer lies in the history of Europe's medieval era. The elite and the royalty lived with the perpetual fear of poisoning. One way of ensuring that your host, with his complete control over cooking and serving, did not poison your food was to sit around a table with food heaped in the centre. Everyone ate the same food.

For that very reason, declining a lunch or dinner invitation was equivalent to saying "I don't trust you". The converse is also true.

Men seem to like violence. History is replete with stupid, lame excuses which were used to justify wars.

The Pig War took place in 1859 when the USA and the Great Brits clashed in the San Juan Islands. The immediate provocation came from an unmannered pig, who, true to its nature, was feasting on tubes.
after trespassing into a farm across the border.

Greece and Bulgaria got involved in a proper war, when a Greek soldier inadvertently trespassed into the Bulgarian side and got shot at while chasing his own dog, which had unknowingly crossed over to Bulgaria. The war that ensued did not start on an impulse. Rather, there was a public outcry and demand for a war as retribution.

History of war is replete with many such funny stories. What is not funny is our natural proclivity for war. Psychologists have long argued that men love violence, given their tireless efforts at keeping the tradition of war alive by internalizing it in every human culture. Things got more obvious when mythologies literally glorified war.

It was late when pacifists, after the WW2, started creating an alternative social narrative. But the latter lost steam when it got merged with the much broader counter-culture movement of 1960s.

Meanwhile, medical research figured out finally why men love war. Actually, they love violence. The male sex hormone, testosterone, is the causal agent. Testosterone handles distinct masculine features like facial hair, heavy voice, more muscle mass, etc. When it acts on the brain, it makes humans aggressive and violent.

During the hunter-gatherer days, men used to hunt. So it made evolutionary sense for them to be naturally violent. But in today's peaceful times, that trait is highly counter-productive. So are many of our stone age cerebral constructs which continue to create cognitive dissonance and negate much of our hallowed rationality and judgement. It creates monsters like Hitler and Mao, faceless perpetrators of domestic violence, mass shooters and serial killers.