Desperately scrambling to save what appears increasingly like a stillborn US peace initiative, the administration bowed to the inevitability of Israeli retaliation for the weekend killings and made one more appeal to the Palestinian President, Mr Yasser Arafat, to crack down.
The Israeli Prime Minister, Mr Ariel Sharon, according to US officials, told President Bush when he met him on Sunday before flying home that Israel would "do what we have to do to protect our citizens". And the administration made no bones about its right to do so, with the President's spokesman, Mr Ari Fleischer, telling journalists yesterday as the bombs fell on Gaza that Israel is a sovereign nation.
But he also reiterated language used by the US Secretary of State, Mr Colin Powell, on TV on Sunday, urging both sides to weigh the repercussions of their actions.
Such muted criticism - more appropriately described perhaps as friendly advice - is partly a reflection of Washington's own vigorous assertion of its right to self-defence in Afghanistan. Pointedly, Mr Sharon, inscribed the White House visitors' book with the words: "My admiration for your courageous leadership in the fight against terrorism."
However, it is the sheer scale of the killings that has changed the nature of the debate and reignited a discussion in Israel about the advisability of toppling Mr Arafat.
The US pragmatic calculation is that it cannot afford to confront the Israeli Prime Minister, Mr Sharon, too forcibly at present if it wishes to side with moderates in his Cabinet to influence him not to take that course.
The State Department is still convinced that the alternative to Mr Arafat is inevitably going to be a more difficult interlocutor and would spell the end of the two-week-old US re-engagement in the process through the US special representative, Gen Anthony Zinni.
Emphasising those fears Mr Powell also warned Mr Arafat personally over the weekend that he faces "a moment of truth" in which not only are Israeli interests at stake but crucially his own authority as a political leader. He is also understood to have made clear to Mr Arafat that the US will not be able to continue dealing with him if he does not clamp down on both the perpetrators of the violence and "future perpetrators", specifically Hamas and Islamic Jihad.
"The President made clear what he demands of Chairman Arafat and the Palestinian Authority: the immediate arrests of those responsible for these heinous acts and decisive action against the organisations like Hamas and Palestinian Islamic Jihad that support them," Mr Sean McCormack, spokesman for the National Security Council, said of the meeting between Mr Bush and Mr Sharon. "If Chairman Arafat is going to be a leader, it's time to step up."
Gen Zinni's mission will continue, but is made harder by the practical difficulty of shaking Mr Sharon from his insistence that peace talks cannot begin without a full seven-day period of peace. With the momentum of the peace process in the hands of those willing to inflict suicide bombings, the prospects are not seen here as good.