Ruthlessness

Etymology

From Middle English "ruthe" (pity, compassion), from "rewen" / "rue" (to feel sorrow or regret), Old English "hrēowan." "Ruth" once stood alone as a word for pity; it has all but vanished, surviving mainly in its negation, "ruthless."

noun · /ROOTH-lis-nis/
A willingness to pursue one’s ends without pity or moral restraint.
What it names
The trait of setting compassion aside to get what one wants — admired in strategy, feared in people.
Example
She restructured the company with a ruthlessness that saved it and cost her every friend she had there.
Related idea
Callousness is a failure to feel; ruthlessness is a decision to override feeling. The ruthless may feel the full pull of pity and still refuse it.