The veto is almost sure to embolden the government of President Bashar al-Assad, which brazenly carried out the assault on Homs on the very day the Security Council planned to vote. It came, too, around the anniversary of its 1982 crackdown on another city, Hama, by Assad's father, Hafez, in which at least 10,000 people were killed in one of the bloodiest episodes in modern Arab history.
"This is a license to do more of the same and worse," said Peter Harling, an expert on Syria at the International Crisis Group. "The regime will take it for granted that it can escalate further."
The Security Council voted, 13-2, in favor of a resolution backing an Arab League peace plan for Syria, which calls for Assad to cede power to his vice president and a unity government to lead Syria to democratic elections. But passage was blocked by Russia and China, which opposed what they saw as a violation of Syria's sovereignty.
The support of those countries has proven crucial in bolstering the regime's confidence, despite an isolation more pronounced than any time since the Assad family seized power more than four decades ago.
After the vote, and the failure before that of the Arab League peace plan to stem the violence, predictions were grim about what lay ahead in a conflict that the United Nations says has claimed more than 5,000 lives. To many, two inexorable forces were at work: a government bent on crushing the uprising by force, faced with an opposition that appears to be radicalizing and growing in determination.