Russia invades another country. You are the President of the US. Your options are:
1.) Do nothing. Poland, and the parts of Germany that used to be East Germany, might not like the long term consequences of this plan.
2.) Start a nuclear war, killing hundreds of millions of people. A few disadvantages to this plan as well.
3.) Economic sanctions. You can certainly say this will kill people by way of depressing GDP growth. Will it kill fewer people than a full nuclear exchange between the US and Russia?