What forces are involved in achieving launch?

Well, there obviously gravity and lift. But there are two more. They are drag and thrust. Gravity operates all the time. Then you give thrust to the aircraft, to create lift, and drag will automatically operate. Gravity pulls you down, lift pushes you up, drag slows you down and thrust accelerates you. Gravity and drag are both bad for launch. Lift and thrust are absolutely essential for launch. So there you have it.

Gravity, Lift, Thrust, Drag