U Thant visited Cairo and reported to the Security Council on May 26 that President Nasser assured him that the UAR would not stage a preemptive attack against Israel. Nasser was still insisting that his call to withdraw UNEF and his troop deployment related to the Israel-Syria situation. He said at a news conference in Cairo, “We could not remain silent in the face of threats to Syria or any aggression against her.” These actions by Egypt were later seen, doubtless correctly, by Quincy Wright, professor at the University of Chicago, as aimed at deterring an Israeli invasion of Syria or at allowing Egypt to attack Israel in the event of an invasion by Israel of Syria. Neither Thant nor any of the major powers thought Egypt would initiate hostilities. With Israel claiming casus belli over Egypt's shipping restrictions, the Western powers regarded Israel as the party that might strike, and they looked to solving the straits issue as the way to keep Israel from attacking.

The British cabinet was focused on securing safe passage through the Straits of Tiran as a way of deterring Israeli military action against Egypt. British Minister Thomson suggested an escort operation for ships sailing into the Gulf of Aqaba, staged by naval vessels of the United States and Britain and other maritime states. US Secretary Rusk said that the two powers “should endeavor to persuade the French, Italians, Scandinavians and as many others as possible to join.” President Johnson, in a television address on the Middle East, affirmed the US position that the Gulf of Aqaba was an international waterway, and that Egypt's restrictions were illegal. Prime Minister Wilson sent Johnson a detailed proposal on how a naval escort might be arranged, relating that the British government was working on it urgently. Wilson kept Soviet Chairman Kosygin informed, convinced that the USSR was anxious to “avoid an escalation into a major confrontation.”