International politics are cutthroat. Smaller nations have generally grouped together in regional confederations--France, for instance, is embedded in a European bloc--while the Great Powers of the United States, Brazil, India, and China went their own ways. China has recently gone fairly low-key and chose to become a non-hegemonic member of an East Asian bloc, but the other three Great Powers are quite active. Back in 2115, the Great Powers nearly came to blow over Chinese plans to establish an enclave in the failed state of Surinam. Most recently, Turkey's decision to change its system of government from "Electronic Democracy" to "The Matrix" provoked a largish regional war, as the artificial intelligences controlling the Turkish government precipitated a largish regional war against Russia and Arabia. The war ended with the deposition of the dysfunctional system of government, though not before the other Great Powers and blocs risked being dragged into the conflict.
The game is fun, but the players are aggressive. To a certain extent this is because of the truism that people roleplaying countries are often significantly more aggressive than those very same countries would be in real life. One factor that shouldn't be underestimated is the fact that memberships in the various blocs and hyperpowers don't overlap, and whatever cooperation does exist tends to be aimed against potential competitors. With no institutionalized dialogue, there's one reason less to send your fleets and FTL gunships to fight.