What does aggressive preparation for war mean?

Building factories, making tanks, aircraft, guns, army clothing, and so forth. Also included would be making defensive positions like walls, or tank traps on the seashore.

Also, drafting young men and women and training them to fight, or to support the fighting troops. Stationing groups of troops, airplanes, ship, and so forth in a locations close to the (presumed) enemy. Some warlike countries sail their ships into other countries' waters, sort of like daring their people to do something about it.