Clinton & co. saw a red lining of hope on the eve of the vote in the UN Security Council, Russia had not suggested further emendations. But the Russkis fooled her. Russia, joined by China, cast a veto killing the resolution.
The US can huff and puff all they want, but they've little cause to complain: simply look at the number of vetoes they used when it was question of condemning Israel!
America does not take rebuffs lightly, yet, like it or not, they may think that they are the cock of the walk but, in truth, they do not always get their way.