How much time do you have until Basic?
For the military, as you probably know, the training is mostly aerobic. In order to meet these demands, you need to hypertrophy your slow twitch fibers and make your fast twitch fibers more oxidative. You also need to work on your cardiovascular system, like your heart.
Focusing on conditioning doesn't make your muscles go away. You want to keep your fast twitch muscles and just make them more oxidative. Depending on your abilities and time left, you can continue to strength train while working on conditioning or you can put your strength work in maintenance by lifting just once a week.