Prime Minister Benjamin Netanyahu's Knesset speech on Monday was a good one. He told the truth. He described the Israeli-Palestinian conflict as it is. He set down six principles for Israel as it seeks peace: recognition of Israel as the Jewish national home, a demilitarized Palestine that does not control the Jordan Valley, a solution outside Israel to the refugee problem, retention of settlement blocs, a united Jerusalem and a declaration of an end to the conflict with no further demands.

These six principles are completely loyal to the Rabin legacy, the Sharon legacy and the Kadima party's platform. They are principles that can be legitimately presented to the Palestinians. They are principles that can be explained to the world. They are principles that the sane Israeli majority accepts. Regarding Jerusalem, Israel will have to make another painful concession, but basically there's no two-state solution that is not founded on these six principles.

If we deserve peace, these are the principles it will be based on. If war is imposed on us, these are the principles that will be worth fighting for. This is the Israeli core.

But Netanyahu's speech to Congress next week will have to be even better than Monday's; it will have to be excellent. To achieve this, he will have to include another principle of peace that he didn't mention in the Knesset - the principle of 1967.

Israel's prime minister doesn't have to agree to withdraw to the 1967 borders. Such a withdrawal is impossible. But he will have to agree to give the Palestinians land equivalent to the territory captured in 1967. Such an agreement is vital. Without accepting the principle of 1967, Netanyahu's other principles will remain full of holes. The Palestinians will mock them and the world will reject them. They will end up the latest unimportant remarks by an unimportant prime minister who left no lasting mark.

The draft of Netanyahu's speech to Congress is ready, and it includes a brilliant idea. On Tuesday, that flash of brilliance will make headlines. But after Tuesday, there will be a stormy debate both in Israel and around the world: Is this great idea merely spin, shtick or a breakthrough? An evasive maneuver or a substantial declaration?

Precisely for this reason, Netanyahu must craft his speech carefully. Just as his Bar-Ilan speech is remembered for seven words, his Washington speech will rise or fall on some 30 words. If they are uttered sincerely, with determination and strength, they are likely to be a turning point. If they are muttered vaguely, they will accomplish nothing. Only a brave Netanyahu will manage to challenge the Palestinians and the international community. Only with a substantive statement can he create a new diplomatic reality.

These are tough times. The Middle East is roiling and the Palestinians are on a roll, which is making them more and more extreme. There isn't much chance for peace now. But if the United Nations decides to accept the establishment of a Palestinian state along the '67 lines, there will be no chance for peace in the future, either.

If the world decides to realize the Palestinians' right to self-determination without their renouncing their demand for the refugees' return, they will never concede the right of return. Three million Palestinian refugees will make peace impossible. If the world concedes Ma'aleh Adumim, Gilo and French Hill to the Palestinians, they will never compromise on Ma'aleh Adumim, Gilo and French Hill. Six hundred thousand settlers standing in peace's way will assure that there will never be peace. September 2011 will be remembered as the month that peace was lost.

The ramifications are hard to swallow; the current battle is not over peace now, it's simply over leaving a path open for peace in the future. At the same time, the battle is against Israel's total delegitimization, against sliding downhill toward war, against creating such a feeling of despair that Israelis and Palestinians will end up at each other's throats.

Under such grave circumstances, all sane people must band together. Netanyahu must move things forward by adopting the principle of 1967. Kadima must give Netanyahu a break by adopting a positive attitude - one that is practical, not spiteful.

All Israel must unite around these core principles, and the international community must get real. Only thus, by joining forces, will it be possible to prevent war and move gradually toward peace. There is very little time. The iceberg is getting closer.