Thoughts about "Wars"

Sometimes after a match you hear it described as "an absolute war" or something similar.

What do you think constitutes a war, and what would be a good example of such? Does it have to be a long match? That would rule out the Shibata vs Ishii G1 match. Does it have to be strong style? That would rule out most WWE matches? Blood? Weapons?

Is it just selling exhaustion of being at a physical limitation, or something more intangible?

What components must a war have, or not have?