Frum makes the necessary case:
First, as the patron of the region’s pre-eminent military power, the United States gains leverage and status. Arab states that cooperate with the United States (e.g. Egypt) get what they want from Israel. Arab states that do not cooperate (e.g. Syria) do not get. The US can deploy Israel’s power to rescue other US clients from enemies (as the Israelis rescued King Hussein of Jordan from the PLO in 1970) or to accomplish strategic missions that the US would rather not dirty its own hands with (the destruction of nuclear facilities in Iraq and Syria, the assassination of terrorist leaders).
Second, Israel is a huge source of information to the US and the most valuable live-fire test laboratory for US military equipment and doctrine.
One of the decisive moments of the Cold War, for example, occurred during the skies over Lebanon in 1982. During the Yom Kippur war of 1973, only 9 years previous, Soviet ground-to-air missiles had wrought havoc upon Israeli aircraft. This time, Syria scrambled its air force to meet Israeli planes: 150 against 150, the largest air battle of the jet age. In just a few minutes, the Israelis downed 86 Syrian craft, suffering no casualties of their own. Microelectronics had triumphed in the test of battle. Soviet histories generally credit this event as the shock that jolted the Soviet elite into realizing that it must try some kind of “perestroika” of its ossifying economic system.
Third: the demonstration effect of the superiority of Western ways in interstate competition. Israel in 1950 had an income per capita not very much higher than that of neighboring Syria. Today, Israel has a GDP per capita comparable to that of most European countries, and higher than that of Saudi Arabia. It has sustained democracy under military onslaught. It is a science and technology leader. The Arab world may not like Israel, but its success sends a powerful “If you can’t beat them, join them” message. And of course part of “joining them” is emulating Israel’s close relationship with the United States.