Type 1 diabetes is not a major disability. They should have every right to sign up for a military career. For some Americans the military is the only option, this is the same with some diabetics. They have to pay for insulin and supplies which can cut into their college funds. If a diabetic could join the military and support their country then they could get benefits to help cover this life long cost. Some families only do military operations, so it makes type one diabetics into a black sheep.
Everyone should have a right to fight for their country and pay back what they owe american in some way if physically possible.