In 1950 ASB makes the US topple the Saudi regime

The US intervention in Lebanon 1958 [and quite possibly Lebanese Nasserites or Arab Nationalists' power struggles with incumbent Lebanese President Camille Chamoun] had precious little to do with the Israeli-Arab conflict in the Palestine issue.

President Chamoun [who was a Maronite Christian] called for western support, and America answered with intervention, because he was under domestic political attack by forces that wanted to unite or at least align with the United Arab Republic, the federation of Egypt, Syria, and Yemen at that time, led by Nasser, that was seen by Washington as 'tilting' toward Moscow geopolitically, and was in fact relying primarily on the USSR for its arms imports. Nasser's de facto foreign policy was fairly Soviet aligned, but repressive against native Communist Party members in Egypt and Syria. His formal foreign policy was "Non-Aligned" which meant emphatically rejecting western alliances like the Baghdad Pact and CENTO, and hounding regional Arab leaders who participated in such alliances.

By asking for support, Chamoun put the recently announced ''Eisenhower Doctrine" to support Middle Eastern countries "against Communism, or forces controlled by Communism" to the test. And Eisenhower support intervention in favor of the pro-western Lebanese leader against his anti-western opponents to show strength in the aftermath of the complete collapse of the Iraqi monarchy, which had been the linchpin member of the Baghdad Pact to contain Soviet-backed Communist, to a surprise coup by radical nationalist officers. The Iraqi radical nationalist officers expressed an admiration of Nasser, formally non-aligned, anti-western, open to the eastern bloc policy, so Washington did not want to be seen to "lose" more countries to radical "momentum" at this time.

Fortunately, the US intervention in Lebanon 1958 was brief, there were no real combat engagements for US forces, there was a compromise political settlements, and no loss inflicted upon or inflicted by intervening US forces at that time.

Around the same time as the Lebanon intervention, I believe the British SAS may have intervened to shore up King Hussein in Jordan against similar challenges. King Hussein was even more alarmed by the events of the Iraqi revolution, because it was his own cousins getting massacred in the overthrow of that other Hashemite monarchy.

Back in the 1940s and 1950s, although Israel certainly received US financial aid and acquired American arms via black market means, it was not an official customer of US arms, or recipient of US military aid or ever offered a US alliance - it's biggest arms purchase during its war of independence came from Czechoslovakia, and never could have gone through completion without Soviet permission. In the 50s, France, followed by Britain and West Germany were Israel's biggest sources of arms, rather than the USA. Whereas the US in one or more instances, offered multiple Arab states including Egypt, Syria, Iraq, Jordan, Libya, Morocco and Saudi Arabia alliances or basing deals. Egypt, Syria, and Jordan consistently rejected US alliance deals for domestic political reasons. The Iraqi monarchy accepted the Baghdad Pact with the west in 1955 but was soon overthrown in 1958, with foreign policy orientation being one of the military and public's main complaints. Libya accepted a US basing deal which remained in force until the 1969 overthrow of King Idris. Morocco and Saudi Arabia accepted base leasing deals.

So Nasser's tussling about in Lebanon was more about expelling more distant western (French, British, American) than local (Israeli) influence in Lebanon. And Israel wasn't see by western governments in the 50s as a strategic asset, but instead as sort of an embarrassing forced charity project/experiment.

In fact, it took another decade of Nasser continuing to play the anti-western/pro-Soviet card, against several targets, conservative Arab states, the US, UK, Britain, and Israel, and then the Israelis smashing him in 1967 and then deterring Syrian or Iraqi intervention in Jordan's Black September 1970, to make cynical Americans start to think of Israel as a useful Cold War strategic hammer to smash troublemakers.