France and Britain acted upon provocation by President Nasser and together with Israel, they secretly planned a joint attack on Egypt, hence the infamous collusion meeting (Oct 1956) and the Protocol of Sevres. Egypt though militarily defeated, they gained a political victory as they managed to stir up Arab anti-west and anti-Israel nationalism throughout pan-Arabism.
Cold War was a major contributing factor in the conflict from 1956 to 1973 as the superpowers jockeyed for influence, resources and strategic gain. In the 1967 Six-Day War, Israel invaded Egypt, Jordan and Syria in a pre-emptive strike. These pre-1945 tensions were triggered by long-term issues of Israel’s quest for security and recognition and the Arab states’ belief that they could defeat Israel and liberate Palestine if sufficiently armed. The superpowers continued and increased involvement after 1967. USSR increased support for the radical Arab states and also spent billions to develop port facilities in Egypt to support their naval presence in the eastern Mediterranean. The US too began to view Israel as a strategic asset, a bulwark against the Soviets and its clients and a bastion or order in the region.
US support for Israel for non-Cold War reasons has contributed to instability throughout this period. America has not only funded and armed Israel but it has also contributed to instability by failing to restrain Israel and force to make peace. This is prevalent by US vetoes of UN resolutions condemning Israel. This held back the process of passing a resolution and bringing peace and stability to Middle East. On top of that, US acted as a contributor to rise of Islamic fundamentalism. Hamas was formed as a reaction against continued Israeli occupation and to express their desire to create Palestinian Islamic state on all of Israel. HIzbollah too was formed as a reaction against Israeli actions.
However, there were some instances where external forces have attempted to stabilise the region and bring peace, if not entirely successfully. France and Britain were condemned and pressured by the US to accept UN ceasefire under economic sanctions. Israel was also pressured by the US to return territories to Egypt. The 1956 Suez Crisis showed the strength of the US as a superpower in the face of local nationalism.
Also, while the Cold War superpowers increased tension, they also attempted to contain them in some ways. The early 1970s was a period of détente between the US and USSR. Both nations adopted an ambivalent policy and wanted to restrain their respective clients from wars but failed to do so. However, the superpowers were dragged into war by supplying their clients with military aid to prevent from switching alliances.
The superpowers were more actively involved in the 1973 war. The last phase of the war despite being the most serious superpower confrontation in the Middle East, they eventually worked together to stop the fighting. At the 1979 Camp David Accords, Israel and Egypt signed a peace treaty, the first between Israel and an Arab state with US mediation.
Mostly importantly, the role of the Norwegians in facilitating the 1993 Oslo Accords which offered the possibility, for the first time, of a two state solution to the Israeli-Palestinian issue. In the 1991 Madrid Conference, USSR, US and Spain invited leaders from the Middle East to Madrid to discuss possible peace proposals, which later developed into the Oslo Accords. The Oslo Declaration included recognition of Israel’s right to exist, PLO as official representative of Palestinian people and the end of us of violence.
In conclusion, after 1973, it is possible to suggest that external forces became more a force for stability as superpower rivalry in the Middle East ceased, and as the US began to play a larger role as peacemaker.