Explain that brainwashing can be so effective that say a person from country "X". Can manipulate a person into bad or ill thought behaviour against the country "X". So that the manipulated person's actions can be engineered to trigger the creation of an artificial motive. That motive can then serve as a way to convince others that actions against the manipulated person are justified and worthwhile. Thus creating an artificial enemy. Who is essentially just an angry and confused person. Keep it short.