> People want realism to be a theory of how the world actually works, a theory of how the world should work, and a theory of what should we do given how the world works, all at the same time.
In terms of presenting an accurate model realism is only as good as the analysis you put into it, and unless you have a very advanced computer simulation of the world you can't test these models for what exactly will happen and when. Sometimes your prediction will be reasonably accurate and sometimes it won't, and hindsight bias will play tricks.
And as for its usefulness for deciding what we should do there seems to be little provision for the role of ideology, ethics, a sense of honour etc, i.e. what kind of world people would like to live in. Those factors are critical not just for making a model of current and future realities, but are of course essential for figuring out how we want to shape our world. A purely utilitarian view just aiming to minimise war and death might permit a more highly autocratic and repressive world, which could be at odds with many people's view of meaning and personal or collective destiny. An example of such a destiny would be the Ukrainian people's desire to live in a democractic Western-aligned state, and the West's desire to support them in this goal.