The United States has used its veto at the United Nations Security Council to block a resolution which called for international monitors to be sent to the West Bank and Gaza Strip.
Although America uses its veto in the council only rarely, it was the second US veto this year against a resolution proposing an observer force.
The resolution - at the suggestion of France - this time contained an amendment condemning all acts of terror, especially against civilians, but the United States ambassador to the UN, John Negroponte, still maintained that it was one-sided.
He said it did not specifically mention the recent suicide bombings against Israelis, or the organisations responsible.
"Unfortunately the resolution before us fails to address the dynamic at work in the region," said Mr Negroponte.
"Instead, its purpose is to isolate politically one of the parties to the conflict through an attempt to throw the weight of the Council behind the other party."
Arab resolution
Any monitoring force in the Middle East would inevitably be more effective against Israel than against groups like Hamas, simply because the Israeli Government is using conventional forces against the Palestinians, not lone suicide attackers.
The Palestinian representative at the UN, Nasser al-Kidwa, was disappointed - if not surprised - by the American veto, but said he felt something had been achieved.
"In spite of our regret at the blocking of the resolution by the veto, nevertheless we think that the proceedings of the Council and the number, the voting pattern, will send an appropriate message to both sides, and hope it will contribute to bring about a better situation on the ground," he said.
The resolution - sponsored by Egypt and Tunisia - had also called for an immediate stop to all acts of violence, and the resumption of talks between Israel and the Palestinians.
The United States was the only Security Council member using its veto.
Britain and Norway abstained, and all the other members, including France, Russia and China, supported the resolution.