That is definitely something to think about. You won't be in the air force forever. Maybe it's 5 years; maybe 10; maybe a 20 year career; or maybe even 30 years. Now, if you make it 30 years, and are obviously a general, you'll be approximately 52 years old. You will probably have enough money in military retirement and savings that you won't "Need" a job. You might "WANT" a job, but that's different than "Needing" a job. However, if you only stay in 20 years, or less, then you will most likely "NEED" to continue working. This is where "Maybe" your degree is useful, maybe not.
You could have a history degree and possibly become a procurement officer. You might deal with contracts and such for a living. After 20 years in such a field, that experience is what will get you your next job; not your degree. Same if you become an intel officer.
You definitely need to look at what you want to be "When you grow up". Hopefully, you'll try and major in a degree, in an areas that you want to serve in. It will definitely help you later on when you are choosing your job. The unique career field is pilot. Your degree doesn't have to have anything to do with being a pilot. And if you want to continue being a pilot when you get out of the military, then the degree still doesn't matter. But if for some reason you want/need to do something different, your degree might be important.
Remember also; in order to become a permanent major. (Not sure if it's called that still); but basically in order to be "ALLOWED" to stay in the military long enough to be able to receive a retirement, you will have had to have gotten your Master's degree by then. I.e. They are not going to allow you to stay in the military without a master's degree. So, when it comes time for your graduate degree, you can always choose something more "Practical" instead of history or english. Maybe an MBA Business; Counseling; management; IT; law, (That's higher than grad school, but still more education).
So, I really wouldn't worry too much right now. If you want to make the air force a career, and you HAVE to go to grad school, you can work that out then. If you plan on a 5 and dive, or out by 10 years, and aren't sure if you will go to grad school, you might want to consider an undergraduate degree that has some practical use. best of luck. mike....