It depends on the situation. What will determine if the patient can stay in the military or not is whether they can meet the universality of service requirement. In the case of diabetes, it is not the condition that is necessarily the issue; it is the medication they take that is required to maintain their health. If the patient can function with oral medication, then there is normally no issue unless there are other conditions for that patient, but there is no issue with staying in the military.
If they are at the stage where they require insulin, because the complications of not taking their insulin can be dramatic for a patient.... In our military operation we may be in a situation where the patient may not get access to their medication for days, and that may not allow the patient to stay in the military for that reason. This is not only for diabetes. It is true for any condition.
In a case where a patient gets a medical condition, physicians would be looking at the medical condition first and then the drugs. They would see, based on that, if the patient could still meet universality of service. We do not have a black and white rule. All of them are assessed case by case.