Another great entry by Ian Welsh describing what he considers to be the three fundamental rules for public policy: do no harm, be kind, remove the ability or reason for people to do harm.
If someone runs out of money, we don’t want them to lose their primary residence. Even if you are soulless, you shouldn’t want a society that creates homeless people; it takes far more money to support someone on the street than it does to pay for almost anyone’s mortgage or rent. We don’t want people who are sick to be denied health care because they become pools for disease. We’re treating these people eventually anyway (when they turn 65 or become so poor they qualify for Medicaid), which is far more expensive than dealing with their illnesses when they first present themselves.
We don’t want to destroy other countries (Iraq, Afghanistan, Syria, Libya, etc.) because their people become refugees with whom we then must contend; this produces scads of angry people, some of who may wind up killing us, and it further ruins their economies, rendering them unable to buy our goods (except our weapons.)
Damage to others who live on the same planet as you can come back to haunt you. Damage to others in your own society will come back to haunt you.
So, first, do no harm. Yes, there are exceptions, but they are radically rare. Almost every bit of harm we do to others through government policy is a bad idea.