Impatiens on Nostr: If the United States of America encourages/ sells weapons to boost other countries' ...

If the United States of America encourages/ sells weapons to boost other countries' defense arsenal without a contract clause preventing such actions, are they at fault for the subsequent destruction and/or human deaths from 'munition clearing' (lets call it)? If they have done this type if action before, would it count as a war crime? Could anyone calculate probability based on manufacture date any type of munition (and published half life per munition)?