States typically fight over territory:
Land supports a population, which provides the state with taxes and army recruits. It can also have strategic value, if it allows the state to project power or control a choke point. And, of course, states are essentially territorial entities: without land, they are nothing.
States often behave in an opportunistic manner, grabbing real estate when they can and giving it up when the cost of holding it becomes too great. In 1732, Russia returned a large chunk of Persian territory that Peter the Great had conquered in the previous decade. In return, the Persians entered an alliance with the Russians against the Ottoman Empire. This kind of behaviour is well-described by realism. However, most states, historical and modern, also put some territory into a special category, one that is not subject to rational geopolitical calculation. Such land is ‘sacred’. It must be held at all costs.
Here we find an obvious manifestation of the bourgeois strategy in the hawk-dove game. States and populations that are willing to escalate conflict as far as necessary in defence of their sacred lands are more likely to persist in the international arena. Those that treat their core territory in a rational manner — forfeiting it in accordance with strategic imperatives, as, for example, several Germanic tribes did repeatedly during the Migration Period — get wiped out. As a result, we observe the coevolution of geopolitics and what the anthropologist Scott Atran has identified as ‘sacred values’. Geopolitical assets acquire an aura of sanctity.