Small-scale military actions, which would eventually escalate into the Vietnam War, started in the late 1950s, when South Vietnamese President Ngo Dinh Diem instituted an anti-Communist campaign aimed at rooting out "left behind" Viet Minh forces. At that time, North Vietnam was hoping for an election, promised under the Geneva Accords of 1954, that would unite North and South Vietnam. It was also worried about inciting the United States into directly supporting South Vietnam, and had recommended a policy of avoiding battle at all costs. However, Diem's campaign was too successful to allow them to do nothing, and small-scale actions broke out across the country. North Vietnam remained worried about US involvement and refused any sort of military support, forcing the remaining Viet Minh to retreat into inaccessible areas in the hills and river estuaries. A stalemate of sorts followed, as South Vietnamese forces took so long to reach these areas that the guerrilla fighters were able to retreat with little difficulty.