I have always been interested in a TL where America supports the Arabs while the USSR supports Israel, so here is an idea for that scenario:
Lehi kills Harry Truman in 1947, leading to George Marshall becoming president. Marshall IOTL was anti-Israel, didn't want to recognize and instead wanted to strengthen ties with the Arab states. While his presidency will be short (he was apolitical and was averse to running for political office) it will still leave a lasting legacy with regard to America's relationship with the Middle East.
Sometime in the 1950s the Lavon Affair is carried out, making the United States even more anti-Israel and the UK becoming distrustful. Only very intense negotiations prevent war.
Flash foward to 1967. Here the United States is not embroiled in Vietnam, or in any other country for that matter. During the Six Day War, the USS Liberty incident still happens. After this, the United States declares war on Israel.
What happens next?
Lehi kills Harry Truman in 1947, leading to George Marshall becoming president. Marshall IOTL was anti-Israel, didn't want to recognize and instead wanted to strengthen ties with the Arab states. While his presidency will be short (he was apolitical and was averse to running for political office) it will still leave a lasting legacy with regard to America's relationship with the Middle East.
Sometime in the 1950s the Lavon Affair is carried out, making the United States even more anti-Israel and the UK becoming distrustful. Only very intense negotiations prevent war.
Flash foward to 1967. Here the United States is not embroiled in Vietnam, or in any other country for that matter. During the Six Day War, the USS Liberty incident still happens. After this, the United States declares war on Israel.
What happens next?