> The United States and Israel did not seek, and would not have obtained, a nine-vote majority at the United Nations Security Council. <..> they know they would not have received the votes necessary to pass a resolution even in the absence of a veto.

Interestingly enough it's not true, they even had a non-zero chance to get China's approval to deal with #Iran. That's the usual power struggle in UNSC - the choice was not between US invading Iran and US not invading Iran. 1/2

The choice for China would be between US invading Iran bounded by UNSC resolution, and US doing that bounded by tramp's morality (i.e. nothing.)
China would have strong incentive to agree but impose as many conditions as possible. 2/2
And Iran might got scared enough by the possibility of China's approval, and decide to yield. Not a given of course, but definitely a possibility.