What is the difference between burning and gassing people in ovens and doing it to a whole nation out in the open?

What is the difference between burning and gassing people in ovens and doing it to a whole nation out in the open?

Cambodia wanted no part of SEATO. We would look after ourselves as neutrals and Buddhists.

John Foster Dulles had called on me in his capacity as Secretary of State, and he had exhausted every argument to persuade me to place Cambodia under the protection of the South East Asia Treaty Organization.

Time will inevitably uncover dishonesty and lies; history has no place for them.