Morality is a matter of scale. You can't have morality at the scale of a state, except for one overarching principle and that's survival. You can be pro-Palestine as a matter of personal moral principle; a state can be pro-Palestine for other reasons and pretend that it is due to moral principle. But a state cannot be pro-Palestine actually as a matter of moral principle.
Survival is the only principle guiding all other actions of a state and the best path to survival is power. This is why you maximise your power because that will guarantee your survival; and this is a moral principle (the only one in this large scale) because survival of a state for the coming centuries is about survival and prosperity of potential billions and that trumps losing power to be potentially moral about mere thousands.
This may sound blunt but this is the real principle by which states act (despite the moralistic facade of public relations side of it all). Any moralistic naivete in deviance from this law in a jungle where everybody plays by this rule will result in ruin. In a state of nature, which is the state of international relations, any moral action which does not maximise your power will hence reduce your power and reduce your survival chances.
Obviously seeming moral/amoral and trustworthy/untrustworthy is part of the payoff matrix, hence attempts at maximising your power can actually result in a reduction of your power if the attempts are not seen as acceptable (for moral or any other reasons); this is why states sometimes do the moral thing, as they calculate the amoral opportunistic move will reduce their influence and reputation, hurting their power maximisation in the long run. Of course sometimes the calculation is that you can afford the blow to the reputation as what you get in return will compensate it in terms of power maximisation. The world actors only understand of power; if you're powerful everybody will respect you.
I'm reading into structural realism right now, although in terms of directly reading from books I've decided start more historically with Machiavelli.
I am beginning this journey with a measure of skepticism of the black-box approach to formulating a general theory of state behavior because I find it counter-intuitive to formulate arguments at a macro-level without "micro-foundations", however even in these early stages I can recognize there are obvious and good reasons why this is not done, chiefly I think this is somewhere between very difficult to impossible. I refer to the categories of structural-realist (Waltz, Mearsheimer) arguments about why this "blind-ness" is necessary like so:
1) The argument of inevitability (which you're making): that the pressures/forces of the anarchic international system force states to behave according to their "structural imperative" or optimally for their survival
2) The argument of simplicity/generalizability: that it is not sensible to attempt to account for every factor, and that one can restrict variables in order to feasibly formulate a general theory which is a sufficient approximation of state behavior to be useful as an explanatory vehicle.
A quote from The Tragedy of Great Power Politics: "“States are influenced by the international system, but this does not mean that leaders, ideologies, or domestic politics are irrelevant. They can matter at certain times and in certain cases. Nevertheless, systemic factors tend to dominate because the pressures of anarchy constrain what states can and cannot do”".
What I take away from this is that the pressures of international anarchy function as constraints, but not the entirety of the variables influencing state behavior, and that in the eyes of structural realists, analyzing state behavior according to these constraints as a best approximation has explanatory power.
Looking at the world around me, I just don't see a world insulated from beliefs, and identity complexes in the political realm. Whether it is in the solidarity that countries exhibit with one another, who they choose to form deeper partnerships with, how they structure and select the multi-lateral institutions they participate in.
Would Turkey and Malaysia be signing technological co-operation agreements if not for their shared religion? Would there be an organization of turkic states, without a shared identity complex, cultural practices, and beliefs? Would the EU be possible without the same, or the general solidarity between all the Western countries be possible without the same? On the tin, I think phenomenon like these point to the influence of socio-cultural factors, however constrained by the realities of state-interests within international anarchy.