Economic sanctions are unethical and not effective
The theory behind economic sanctions neglects to account for the fact that impoverished people are more easily affected than wealthy individuals.
Even in instances where economic sanctions work, they are not actually effective. To be effective is to be successful in producing the desired or intended result. Unless the intended result of economic sanctions is to financially and economically hurt the civilians of a country, sanctions are not effective. Most citizens have little say in what their government chooses to do. Imposing sanctions simply punishes an entire group of people for the behavior of a couple powerful and wealthy leaders. Although sanctions that specifically target wealthy leaders cause much less collateral damage, they are not effective enough to justify their existence. These sanctions, such as those prohibiting banks from dealing with a given country, will freeze some of the assets of wealthy leaders. However, it will also freeze the assets of average citizens. The wealthy leaders can withstand long-term economic turmoil. The average citizen cannot. Simply put, sanctions are not effective enough to justify the collateral damage they cause to citizens.
It is expected that sanctions will result in collateral damage. If world leaders see that their citizens are hurting, they will be incentivised to help. Though they may not do so out of compassion, they will do so to retain power. While economically hurting the average citizen is not ideal, it is the lesser of two evils. For example, imposing sanctions on Syria is not ideal and has most likely contributed to the instability in the country. However, allowing trade with a country that openly supports terrorism would have far more violent and thus much worse consequences. In this way, economic sanctions are effective - they are the most ethical of two unethical options.
[P1] Economic sanctions are tools to get world leaders to change their behavior, not to punish average citizens. [P2] However, they achieve only the inverse of this.
Rejecting the premises
[Rejecting P1] Economically hurting the average citizen will cause leaders to change their behavior.