It's very possible, I say 30 years as a more conservative estimate
Support for Israel is entirely propped up by holocaust-brained boomers, once that generation fully passes and no longer control the levers of government power, it's completely over. Everyone knows that Israel was founded by terrorism & naked murder and ethnic cleansing. The entire state of Israel only exists because of an infinite money hose straight from US & other Western taxpayers. Israel is very small and has very minimal economic power - sustaining their advanced defence systems is incredibly expensive, and is only possible from stealing from the Western taxpayer. With that gone, they will be absolutely torn to pieces by the hundreds of millions of surrounding Islamic peoples which they have terrorized, raped, and murdered for almost a whole century. Then, the land will return to the rightful Palestinian residents, and collectively the Middle East will finally have peace, and an actual chance of self determination, unity, & prosperity without every nascent movement being slaughtered in the crib.
I don't think the US would let that happen though, as they are so deep in Israel's pocket, and the brainwashing is so entrenched at this point, I'm not sure that it's so easy as simply waiting for older generations to die off. The education system and entertainment industry are compromised entirely, and Americans live and breath their entertainment.