The K5 Plan for the defence of the Cambodian-Thai border was the response o
f the People's Republic of Kampuchea and its Vietnamese mentors to the thre
at posed by the resistance forces, particularly the Khmer Rouge, to its eff
orts to rebuild the nation and consolidate its administration. The very rea
l defence gains, however, were made at the cost of bitter popular resentmen
t over the way those gains were made.