I cannot understand why the RAF disqualify potential aircrew recruits because of childhood asthma (which is involuntary, the causes poorly understood, and rarely recurs in adulthood), yet the RAF continues to recruit and employ aircrew who smoke tobacco (which is a lifestyle choice which demonstrably causes immediate performance degradation and medium term health degradation). If the RAF were to immediately announce a service wide tobacco ban then the childhood asthma ban might make more sense.