Sanctions indiscriminately harm innocent people, both in the “target” country and at home. To use the word “target” here is inappropriate because, in a globalized economy, sanctions cannot be “targeted.” Their effects are inevitably widespread and felt most acutely by the poor.
Sanctions are ineffective in bringing about their stated objectives. Sanctions have wrought untold and unnecessary suffering for decades in the DPRK and Cuba, for example, without toppling those regimes.
Sanctions provide cover for the incompetence, corruption, and power-lust of dictators who can convincingly blame the West for the deplorable conditions in their countries—and with some justification.
If you support sanctions, you are mistaken to believe that your conscience is clear.