You can be sure of succeeding in your attacks if you only attack places which are undefended. - Sun Tzu

When strong, avoid them. If of high morale, depress them. Seem humble to fill them with conceit. If at ease, exhaust them. If united, separate them. Attack their weaknesses. Emerge to their surprise.

Hiding order beneath the cloak of disorder is simply a question of subdivision; concealing courage
under a show of timidity presupposes a fund of latent energy; masking strength with weakness is to
be effected by tactical dispositions.

[Once war is declared, he will not waste precious time in waiting for reinforcements, nor will he return his army back for fresh supplies, but crosses the enemy's frontier without delay.