It's because that everyone tries to defeat YOU, even when they all are different nations. Especially the 25th level, Isle of Swill, is very hard. And the game is surprisingly harder, when you get to higher levels. After that, you may promote them, but note that good pigs will come much later.
You will start with team of grunts, which are very useless hogs, having only bayonet, rifle and 3 grenades.
Because the nation, who wins the swill, could be the richest nation in the world. 'nationality' of purple pigs decided to war for it. Because swill is very, very valuable in hogs' world and there was very much of it, especially on the Isle of Swill, six most important nationalities of the pigs world and one miscellaneous Grimly found the new continent of Saustralasia, where are big supplies of swill. Before the war, there was peace on the planet.
