Lack of orders is no excuse for inaction.
Do your damnedest in an ostentatious manner all the time.
Take calculated risks. That is quite different from being rash.
War is simple, direct, and ruthless.
Unless you do your best, the day will come when, tired and hungry, you will halt just short of the goal you were ordered to reach, and by halting you will make useless the efforts and deaths of thousands.
Perpetual peace is a futile dream.