As nouns the difference between pacemaker and peacekeeper
is that pacemaker is one who sets the pace in a race, to guide the others while peacekeeper is one that preserves the peace.
pacemaker
English
Noun
(en noun)(wikipedia)
One who sets the pace in a race, to guide the others.
(anatomy) A set of nerves which stimulate the heart to beat.
(hence, medicine) A medical implement that is used to stimulate a heart to beat by simulating the action of the natural pacemaker.
peacekeeper
English
Noun
(
en noun)
One that preserves the peace.
A member of a military force charged with peacekeeping duties in a troublespot.
(Canada, law enforcement) A police officer in a Canadian aboriginal community.