I definitely think that it is moral for the USA to use sanctions to get their goals agains other countries. I think that sanctions are a non-violent way to achieve a foreign matter with a nation that the United States of America has issues and problems with that they want to get resolved.
It is moral for the U.S. to use economic sanctions to achieve foreign policy goals. The use of economic is a peaceful way of encourage countries to comply with U.S. foreign policy. As long as the U.S.'s foreign policy is of moral merit and approved by global organizations like NATO, it is preferable to use economic sanctions to promote foreign policy of other nations.
I personally believe that we should use military intervention as a last ditch effort in a hopeless situation. A lot of conflict between nations are not like that. It is okay to use economic sanctions in order to get what we want so that we don't have to result to war.
It is not moral to use sanctions to achieve foreign policy goals, but sometimes it is necessary. I was for almost all of the sanctions used against Iran and I am for sanctions being used against Russia right now. To me, this isn't a question of morality, but it is a question of acting.