"Disturbance" was used a lot more often than "war," even for relatively large events such as the conflicts that had occurred over the last few centuries between Red and Blue. Because space habitats were so vulnerable, prosecuting an actual war in the sense of a twentieth-century, Old Earth total war was unthinkable. Nuclear weapons had not been reinvented because there was no need for them. A rock thrown across the ring at a space habitat would kill as many people as a hydrogen bomb. The same strategic calculus therefore applied as on Old Earth during and after the Cold War, namely that on no account would Red and Blue risk actual, open war with each other but that many small conflicts could happen in places where they might be passed off, by the majority of the news-reading populace, as too minor to worry about. The only two conflicts that were denoted, in retrospect, as wars were ones that had taken place the old-fashioned way, on the surface of the planet: the War on the Rocks, 4878–4895, and the War in the Woods, 4980–4985.