Brzezinski and Quandt were celebrating President Bush's recently ill-considered words:

The president, in his formal presentation, declared that any final-status agreement between Palestinians and Israelis "must be reached between the two parties, and changes to the 1949 armistice lines must be mutually agreed to."

Lest there be any misunderstanding, the president said that "Israel should not undertake any activity that contravenes road map obligations or prejudices final-status negotiations with regard to Gaza, the West Bank and Jerusalem. . . . A viable two-state solution must ensure contiguity of the West Bank. And a state of scattered territories will not work. There must also be meaningful linkages between the West Bank and Gaza. This is the position of the United States today. It will be the position of the United States at the time of final-status negotiations."

Bush's declaration was a significant and helpful restatement of some long-held American positions. If these principles are actively embedded in Washington's policies over the months ahead, they could help further the president's stated goals of resolving the long-running Israeli-Palestinian conflict, promoting democracy in the Middle East and undercutting support for Islamist terrorism.

Actually if the President betrays the commitment he made to Prime Minister Sharon he will fall into the trap that successive peace processors have. His actions will not bring peace but will extrend the violence.
During the Oslo process every single Palestinian grievance was treated with the utmost respect by the likes of Messrs. Brzezinski and Quandt essentially giving the Palesitnians veto power over any aspect of Oslo they didn't like. Every step of the way Israeli concerns were brushed away (think of Clinton's betrayal of Netanyahu concerning Israeli discretion in the matter of future withdrawals) and Palestinian concerns were treated as inviolable. (Arafat wasn't condemned for starting the "tunnel riots" in 1996; Netanyahu was for opening a doorway!)
The President should follow up on his commitment of last year and make it clear the American government doesn't expect Israel to return to the borders of 1949 or 1967. He should be following his speech of June 24, 2002, headlined "President Bush Calls for New Palestinian Leadership." Yes Arafat has died and the leadership has changed. Perhaps Abbas is not as evil as Arafat but that's not enough. The ideas about Israel's legitimacy and permanence that animated Palestinian nationalism with Arafat still hold sway with Abbas; unless there's a change such an ideology is incapable of making peace.
Terrorism is what brought Palesitnian nationalism to the world's attention. And it is still the currency the Palestinians use to further their cause. Consider how easily threats come to "moderate" Mohammed Dahlan:

"The Palestinians are in a very difficult situation," Dahlan added. "Israel has destroyed our security forces and their headquarters and the international community has given us nothing but advice," he said. "How can they ask us for full results while they haven't given us anything? Israel's current actions are paving the way for a third intifada."

And consider the Palestinian response to Secretary Rice's recent visit:

"Rice didn't come up with anything new," one official told The Jerusalem Post. "She only repeated the same statements which President Abbas heard during his meeting with US President George W. Bush in Washington last month."

Think about, the Palestinian approach to peace alternates between threats and entitlements. It is never about responsibility. That is what Brzezinski and Quandt think should be encouraged.
If fifty seven years of irrendentism and intransigence are still being rewarded by a promise of all of Judea, Samaria and Gaza what is the incentive for the Palestinians to reform and to accept Israel? President Bush needs to stick to his principles and insist on real change. He also must make it clear to the Palestinians that their perfidies since 1993 mean that they will not achieve what they could have achieved then. And that there will be costs to further failures to change.
Telling the Palestinians that they have the last word will only tell them that there is no cost to terror. It will only encourage more.
Crossposted on Israpundit and Soccer Dad.