Were they ever allies? The US had an interest in supporting Israel, in part as a foil to the pro-Soviets (such as Nasser) and as a foil to the anti-western Islamists. No US troops have ever come to Israel’s aid, and no Israeli troops have supported the US in any of its military endeavors. Israel has no treaty of alliance with the US, and has issued no guarantees of Israel’s security. The US does not sell its best weapons to Israel (e.g. the F-22 or any advanced stealth technology). The US and Israel have friendly relations, and in some matters coincidental interests, but they aren’t allies (at least, not in the sense that countries such as Britain, France, Germany, Poland, Japan and Australia are allies with whom the US has a treaty obligation to assist in times of war).