Just war theory

I've been reading some just war theory lately. Many theorists both legal and moral/philosophical explicitly use a self-defense analogy in their reasoning. However, the invasion and occupation of a country by a foreign power for the sake of occupation (and not for some morally justifiable ends such as humanitarian intervention or preventive self-defense) is universally deemed immoral and perpetrating countries are liable to be attacked by the defending country. However, self-defense is usually defined as justifiable only if one's life or "serious bodily injury" reasonably is expected to result from an action of those liable to deadly self-defense measures. The states of Texas, Florida, and I also believe Arizona and Louisiana aside, no state justifies killing as "self-defense" only to protect one's property. Why doesn't this apply to just war theory? Why isn't a war unjust when it is waged for the only goal of occupation unlawful and immoral like the domestic morality and law (except for those states mentioned above) considers when someone kills a burglar when he posed no reasonable immediate threat to the defender's life or was a serious threat to bodily injury? Some people may say that usually, occupations do not bode well for the occupied state with many deaths of civilians coming from continued occupation but this need not be necessarily the case. Some states have no murderous intent in occupying a sovereign state and their intent may be deemed credible by the available evidence. If Norway wanted to invade the US and the reason given is that Norwegians simply wanted to give Americans a better quality of life under Norwegian sovereignty, what justifiable means do we have to defend against such an invasion with deadly force if it is shown that they are reasonably sincere in their intent? Even if Norway wanted some of our resources or land, what ground would we have to kill them in defending that material possession of ours?

Now I believe that it is just (certainly permissible and perhaps justifiable) to wage war on an aggressive occupier or potential occupier to defend one's own country from being unjustly occupied even if that occupation may bring a better life for its current citizens. The rights of the people and the state itself against unjust invasion and occupation justify the use of deadly force even if the occupation does not bring with it any deaths of the citizens if they choose not to resist. But I don't see how the self-defense analogy will provide the moral grounds. The morality of war may be sui generis, or at least very unusual, in this regard.