If you want to go anywhere in modern war, in the air, on the sea, on the land, you must have command of the air.

Meaning of the quote

To win a modern war, whether you're fighting in the air, on the sea, or on land, you need to be in control of the sky. This means having the ability to use the air to your advantage, like flying planes and using air-based weapons. If you don't have this control, it will be very difficult to move your troops and supplies to the places you need to go and win the battle.