As France and Germany urged renewed support for the "road map" -- the U.S.-backed peace plan that some say is jeopardized by Bush's own decision -- the strongest reaction has come from Hamas.
The Palestinian militant group's leader, Abd al-Aziz al-Rantisi, was killed in an Israeli missile attack on 17 April. Al-Rantisi was the second Hamas chief to be killed by Israel in less than a month, following spiritual leader Shaykh Ahmad Yassin's assassination in March.
"Whoever had doubt with that in the past [that the United States and Israel are the enemy], after the Sharon-Bush meeting, I believe that there is no room for doubt," he said. "And this is why, when we study the behavior of the Palestinian people, and we study the behavior of Hamas and the jihad and all the Palestinian factions, and we study what the Palestinian retaliation will be, we study, in this context, that our struggle is with both parties, the first, [the United States,] being the strongest military on the global level, and the second, [Israel,] being the strongest on the regional level."
A Hamas official issued a similar statement after Yassin's killing. But the group later said its struggle was only with Israel. Hamas so far has made no effort to qualify Mashaal's remarks.
Al-Rantisi's killing came just three days after U.S. President George W. Bush backed Israeli Prime Minister Ariel Sharon's controversial plan to pull out of Gaza -- where it has just 7,500 settlers -- but secure key settlements on the West Bank, which is home to around 250,000 Jews.
The killing was condemned in most capitals, but Washington merely expressed concern and defended Israel's right to self-defense.
Israel calls al-Rantisi a terrorist mastermind responsible for scores of deadly attacks against civilians.
Palestinian Authority Prime Minister Ahmad Qureia also accused the United States of giving a green light to the killing. Washington strongly denies that charge -- or that it had any warning of Israel's plan to kill the Hamas leader.
British Prime Minister Tony Blair -- who in the past has been steadfast in his support of Bush's Mideast policies -- offered a reaction to al-Rantisi's killing more in line with that of his European Union partners.
Speaking in the British Parliament's House of Commons in London, Blair said, "We condemn the targeted assassination of Hamas leader Abd al-Aziz Rantisi just as we condemn all terrorism, including that perpetrated by Hamas. We have to break out of this vicious cycle of suicide bombings and retaliation."
As for Bush's decision to endorse Sharon's plan, analysts say it amounted to a sea change in U.S. policy, as Bush did two things that no U.S. president has ever done. He said Israel should not have to give up all land captured in the 1967 Middle East war, and he rejected the right of Palestinian refugees to return to Israel, saying they could instead return to live in a future Palestinian state.
Both of those points have long been considered as being up for negotiation between Israel and Palestinians during final status talks, a point made yesterday in Berlin by German Foreign Minister Joschka Fischer.
"There is no alternative to the road map,” Fischer said. “It is the logical next step to lead to a final conclusion. I, personally, am convinced that agreements which are made by both parties are the solution to this problem. Something that is imposed by one side or the other will inevitably only lead to an escalation of violence and not to a permanent solution to the conflict."
Yesterday, Jordan's King Abdullah signaled his displeasure with Bush's backing of the Israeli plan when he canceled a scheduled visit with the U.S. president in Washington.
A Jordanian statement said the visit could be rescheduled once Washington has clarified its position "on the peace process and the final situation in the Palestinian territories, especially in light of the latest statements by officials in the American administration."
The Bush administration, for its part, said the meeting was put off due to "developments in the region" and that it would be rescheduled for next month.
Jordan's rebuff was echoed by criticism from another U.S. Arab ally, Egypt. Addressing reporters in Paris, Egyptian President Hosni Mubarak said: "Israel has launched itself into a process of organized provocations to assassinate the leaders of Palestinian organizations. It would have been more useful for Israel to maintain the efforts that we are deploying in cooperation with the European Union and the United States to reinforce the Palestinian Authority's capacity to control its territory and its organizations, instead of starting an escalation of violence and counter-violence and threatening the efforts made to help both parties put into practice their mutual obligations with regards to the road map."
French President Jacques Chirac, appearing alongside Mubarak, said the road map is still alive and remains the only viable formula for achieving stability in the Middle East.
The road map calls for a series of reciprocal steps by Israel and the Palestinians leading to peace and a future Palestinian state. The plan was drawn up by the so-called Quartet, comprised of the United States, the European Union, the United Nations. and Russia.
Russia, which has avoided taking sides in the latest Israeli-Palestinian dispute, yesterday dispatched an envoy to the Middle East in a bid to seek common ground between Israel's Gaza plan and the road map.
Moscow has backed Palestinian demands for a meeting of the Quartet, which is now planned for early May in New York.