The Art of War
Here's some cogent battle advice for today's armchair warriors, written 2400 years ago, but still ever-relevant.
"In joining battle, seek the quick victory. If battle is
protracted, your weapons will be blunted and your troops
demoralized. If you lay siege to a walled city, you
exhaust your strength. If your armies are kept in the
field for a long time, your national reserves will not
Where you have blunted your weapons, demoralized your troops, exhausted your strength and depleted
all available resources, the neighboring rulers will
take advantage of your adversity to strike. And even
with the wisest of counsel, you will not be able to turn
the ensuing consequences to the good. There never has
been a state that has benefited from an extended war."
- Sun Tzu, from "The Art of War"