I feel like he for sure will become an antagonist. As he wants to "save the world" but this country doesn't really need that, it just needs protection in cases of crisis (for which Tsukina is well fitted to provide help from the sidelines) I am worried that country that wants to TAKE OVER the world will get to him and twist their motives to align with his (i.e. this world is crooked, we want to bring world peace to everyone, help us achieve this, etc) and then Tsukina will have to get involved.