We can be all but assured of that with friendly countries whose sense of responsibility and of ethics is relatively high. Can we expect the same degree of responsibility and of ethics when the time comes to sell the arms that have been sold to them?
Countries like Switzerland or Germany have a verification process not only before the arms are sold, but also afterwards. That is not the case for most western countries. There are really no mechanisms to verify arms, either before or after the fact.
Can we expect all countries in an alliance like NATO to show the same degree of responsibility and ethics when the time comes to suspend arms sales, thereby penalizing themselves financially and in the knowledge that countries like Russia or China will quickly want to move in?