Of all the myths about writing, the one that provokes the most mischief is that Be concise means “Be brief.” Conciseness and brevity are hardly the same thing, and writers who confuse the two create cryptic, impenetrable, or ambiguous expressions.
We need to modernize our obsolete nuclear weapons tracking system.
We’re guessing if we think we know what’s obsolete in that simple sentence. No hyphen alerts us to whether certain words form a unit; obsolete could relate to weapons or to system. If we read by the code of ordinary syntax, we’d assume that the writer means,
We need to modernize our obsolete system for tracking nuclear weapons.
Unfortunately, the writer intends to convey something quite different: ...