Defense of Israel was the primary justification offered in a recent State department memo asserting the legal basis for the war with Iran. Unusually, its publication was not announced on social media or to the press, unlike most state department official pronouncements. Anyway, rather than being opinion, this is (for the present) the official position of the United States government.
The US has been doing air strikes in the Middle East on a regular basis since ~1990, and they extensively support the military adventures of allies like Israel and Saudi Arabia.