Within six days, in June 1967, the Israeli army devastated the armies of Egypt, Syria and Jordan. It had scaled Syria's Golan Heights, whence it threatened to coast along the gentle plains to Damascus; it occupied Gaza and the whole of Sinai and was able to launch offensive strikes deep into the heart of Egypt; it had conquered East Jerusalem and invested the whole of the West Bank with relative ease. All Fateh's earliest fears about the probable course of a regular-army confrontation with Israel were realised, to the profound shock of the whole of the Arab world.

In Egypt, President Nasser, who had for so long and from a position of such apparent authority counselled the Palestinians against precipitate action against Israel, was himself forced to appear, humiliated, before his own people to offer his resignation. Though the Egyptians clamorously refused to allow him to step down, he had to spend long months and years following June 1967 in patiently patching back together Egypt's military hierarchy, its defences and its popular consensus; he was in no position then to dictate tactics or strategy to anyone else, especially the Palestinians. Similarly in Jordan, whose king was now blamed for ‘losing the rest of Palestine [i.e. East Jerusalem and the West Bank] to the Zionists’ and to a lesser extent in Syria, whose government had been allowing the Palestinian guerrillas a far freer hand than they enjoyed in Egypt or Jordan, even before the Six-Day War: in all these countries, the military defeat at the hands of Israel had sent their governments' negotiating power vis-a-vis the guerrillas plummeting to near zero.