The US has influence over Israeli sales of Israeli-made arms, but this is costly to exert and only used sparingly. Historically, it's restricted to preventing Israeli arms sales to direct US rivals like China or Russia. When Israel sells guns to dictatorships in Africa or Southeast Asia that the US doesn't like, the Americans are perfectly willing to agree to disagree.
EULAs and other civilian contractual arrangements are important here because these weapons were used against US civilians and US civilian property. When Soltam howitzers kill villagers in Myanmar, the US executive branch doesn't give a damn; but as soon as a US corporation (Apple) has to pay for warranty returns the courts wake up and pay attention.
They 100% already do
Devices such as Cellebrite use exploits to extrapolate the decryption key from memory, then use that key on the user storage. This is fundamentally how those tools work. If the device is in BFU, they can't collect nearly as much data.
TL;DR: if you're under threat of having your device taken from you, restart it!
For example, as a New Zealand citizen, I don't expect to have many constitutional rights, nor do I expect I can easily enforce any residual rights I might have using the US justice system (especially against three letter agencies).
https://nationalinterest.org/blog/buzz/israel-wont-sell-awac...
so, the sale didn't go through due to US pressure, but the point is that Israel not only contemplated it, but was going to carry it through.
To set a precedent that they can claim damages for violating their terms and conditions.