Who wins a war? Really think about that. Who are we referring to when the question comes up? If someone gets into a fight with another person you might say that someone "wins" the fight. So and so gets knocked out, or taps out as in wrestling; a person loses and a person wins. Wars however, are fought between countries (that is large tracks of land) but unless you're watching the Lord of the Rings, giant rock people aren't going to be duking it out in the mountains. Who we're really talking about by asking who wins a war is the thousands of people that identify as a member of a "standing army."
The members of this standing army are not independent actors however, they form a group often referred to as "our side" or "our guys." This forms one half of the who we are looking to find. The next aspect to identify is the more ominous sounding "other side" or "those guys," they are the thousands of individuals that identify as members of a different standing army (ooo sounds scary huh?). It should sound scary because "those guys" want to invade your home and kill you. It might sound silly but it's true; by being on "the other side" they really are that dangerous.
On their own these guys on the other side wouldn't be so dangerous. If you met on the street you might even say they are just like you. It's not that being from a different place makes them dangerous, so what is it? It's tempting to say that being a member of this group called a standing army is why, but that would be like saying a member of the chess team is dangerous because they are a member of that group. A member of a chess team however is just in a group that plays chess. A member of a standing army is in a group for the sole purpose of fighting someone else. This argument doesn't really make them dangerous either; boxers, MMA, or even paint ball are individuals and groups that fight each other. What gets dangerous is when a group is trying to kill people from another group. Why then do thousands of people in one group want to kill thousands of people in another group?
Let's get back to this land thing to see if the answer is in there. Unless you are some kind of sea animal (or amphibian), you live on land. Land on it's own has features: hills, valleys, lakes, forests, stuff like that; one feature land does not have is imaginary lines. These imaginary lines are often called "political boundaries." What most people call a "country" is just a set of imaginary lines. So, now we have a line with two sides, we have groups on each side, but no understanding of why thousands of people want to kill each other, and certainly no understanding of who wins.
Sometimes you might have a unanimous decision to kill a single person; like a known serial killer, rapist, or mugger. To go dominating and killing tons of people just for being on the other side of imaginary lines would seem ridiculous to the average person. Large groups of people don't just wander on their own killing each other, so what's going on? Individuals do join groups that together go out killing people, but even then it's being part of the group that drives the groups to kill each other. All the members of the group do have something in common; they don't act for themselves, they follow the commands of a leader. When it's a leader that decides who or what to attack or who or what to defend it's the individuals that joined the group that take the action and the risk.
They do this in reverence for the leader, but not necessarily, because those may change by the day. More so they follow the leaders commands because of a feeling of obligation and being a member of a group. It's also the case that groups have collective stories they tell themselves or that the leaders tell. The belief in these stories forms a world view that is then acted on. The belief that without a hierarchy of control the world would be chaos; this is the belief in authority. The leader is the one to decide actions, to make deals, to reward or punish. And it is the followers job to obey.
The order followers from every imaginary boundary in the world carry out the commands of their leader, believe in their story, and sadly attack and kill each other at the whim of someone they've never met, over deals they were never involved in making.
Now, if it's the order followers going out attacking and defending, winning or losing battles, who wins the war? It's temping to say that whoever’s "side" lost the least people, wins. Or that the "side" who got the most land wins, but lets remember who we are talking about. Can it really be said that destruction and death of more on one side than the other is winning at all? If you come home to ruins you wouldn't say "hooray we won!" The real winner is the one behind the scene, the one who rarely if ever steps out into the field, the "leader." Can the order follower ever say they won anything when everything they did wasn't even their own chosen action? Propelled by the power of a story told by some charismatic person on the radio or T.V. to go destroy "those guys" or to support "our side" isn't winning at all. Like the scene at the end of Dr. Strangelove, the real winners are sitting around a table planning to go into hiding with a ratio of ten women to every male, so they can take on the solemn task of repopulating the earth after everyone is done fighting for something they never understood to begin with; the belief in authority.