What was the activity of the PLO from 1964 to the Six Day War in 1967?
Since Jordan controlled Judea and Samaria (the West Bank) including East Jerusalem, and Egypt controlled the Gaza Strip at the time the PLO was founded, the PLO was committed to the dissolution of Israel, mainly through the use of armed force. Their emblem includes a map — Israel is part of their concept of Palestine.
True to the Palestinian National Covenant, since its founding, the organization has sponsored innumerable guerrilla raids on Israeli civilian and military targets and has been responsible for the deaths of thousands of civilians -- Israeli, Palestinian Arab, and citizens of every country where the PLO has resided.
From early 1965 to the Six-Day War in June 1967, the PLO through Fatah pursued a consistent policy of border attacks, particularly along the Jordanian and Lebanese borders. Criticism of these activities by the Arab governments and by local public opinion persuaded Fatah leaders to adopt a new approach known as "the entanglement theory." This involved using sabotage to force Israel to adopt an offensive position, which in turn would force the Arabs to step up their military preparedness. This cycle of action-retaliation-reaction would lead to a gradual escalation of tension on the borders, and eventually to war. The Syrian military offensive against Israel, with Fatah?s help, among other things, did indeed trigger the Six Day War in 1967, but with disastrous consequences for the Arab armies and governments.
The PLO managed to launch significant terrorist attacks against Israel throughout its existence, with a particularly horrific record in the 1970s and during the al-Aqsa intifada following the collapse of the Oslo peace process.