Note, in a war, it's pretty much the whole point to have the enemy hopelessly outmatched. A fair fight is a crapshoot in that case, and in fact, most battles are decided before they even begin. Competition isn't the point, Sun Tzu had a lot to say about this. And indeed, prevailing even against overwhelming odds, or complete enemy superiority, even if it fails, can be a point of pride, especially for the soldiers themselves (though their generals should be ripping hair off their heads because of that, as their job is not to let that happen). And similarly, steamrolling over the enemy will be mostly a point of pride for one man, namely the strategist who orchestrated the whole thing, while for the soldiers it might be "just another day", and nothing to write home about. And it's tales of soldiers that survive in the folk stories, while strategists' exploits are generally known to other strategists and military historians (unless it's a particularly pivotal battle, that is).
On the other hand, in sports, you're supposed to be pretty much evenly matched. Here, unlike in a war, the "battle" itself is the whole point, and it's always ultimately decided "here and now", when it occurs. For all the planning and calculations, it all comes down to what your players can do. That's why it's generally more common to feel bad about a lost match. Barring extreme circumstances, if you're playing with someone, it's generally someone that you should have even a slightest chance of beating. Otherwise, why play at all? If you're in World Cup, it'd be expected that your team is World-class. Of course, if all teams in your country are shoddy, then it might be hard to get a World-class team out of them, but that is rare. Before a match, you don't know if you'll win or not. You go in intending and wanting to win, even if the opponent happens to have a better record. There are worse teams and better teams, but there are hardly situations in which you can't even hope to win.
