Every Arab-Israeli negotiation contains a fundamental asymmetry: Israel gives up land, which is tangible; the Arabs make promises, which are ephemeral. The long-standing American solution has been to nonetheless urge Israel to take risks for peace while America balances things by giving assurances of U.S. support for Israel’s security and diplomatic needs.

It’s on the basis of such solemn assurances that Israel undertook, for example, the Gaza withdrawal. In order to mitigate this risk, President George W. Bush gave a written commitment that America supported Israel absorbing major settlement blocs in any peace agreement, opposed any return to the 1967 lines and stood firm against the so-called Palestinian right of return to Israel.

For 21 / 2 years, the Obama administration has refused to recognize and reaffirm these assurances. Then last week in his State Department speech, President Obama definitively trashed them. He declared that the Arab-Israeli conflict should indeed be resolved along “the 1967 lines with mutually agreed swaps.”

Nothing new here, said Obama three days later. “By definition, it means that the parties themselves — Israelis and Palestinians — will negotiate a border that is different” from 1967.

It means nothing of the sort. “Mutually” means both parties have to agree. And if one side doesn’t? Then, by definition, you’re back to the 1967 lines.

Nor is this merely a theoretical proposition. Three times the Palestinians have been offered exactly that formula, 1967 plus swaps — at Camp David 2000, Taba 2001, and the 2008 Olmert-Abbas negotiations. Every time, the Palestinians said no and walked away.

And that remains their position today: The 1967 lines. Period. Indeed, in September the Palestinians are going to the United Nations to get the world to ratify precisely that — a Palestinian state on the ’67 lines. No swaps.

Note how Obama has undermined Israel’s negotiating position. He is demanding that Israel go into peace talks having already forfeited its claim to the territory won in the ’67 war — its only bargaining chip. Remember: That ’67 line runs right through Jerusalem. Thus the starting point of negotiations would be that the Western Wall and even Jerusalem’s Jewish Quarter are Palestinian — alien territory for which Israel must now bargain.

The very idea that Judaism’s holiest shrine is alien or that Jerusalem’s Jewish Quarter is rightfully or historically or demographically Arab is an absurdity. And the idea that, in order to retain them, Israel has to give up parts of itself is a travesty.

Obama didn’t just move the goal posts on borders. He also did so on the so-called right of return. Flooding Israel with millions of Arabs would destroy the world’s only Jewish state while creating a 23rd Arab state and a second Palestinian state — not exactly what we mean when we speak of a “two-state solution.” That’s why it has been the policy of the United States to adamantly oppose this “right.”

Yet in his State Department speech, Obama refused to simply restate this position — and refused again in a supposedly corrective speech three days later. Instead, he told Israel it must negotiate the right of return with the Palestinians after having given every inch of territory. Bargaining with what, pray tell?

No matter. “The status quo is unsustainable,” declared Obama, “and Israel too must act boldly to advance a lasting peace.”

Israel too ? Exactly what bold steps for peace have the Palestinians taken? Israel made three radically conciliatory offers to establish a Palestinian state, withdrew from Gaza and has been trying to renew negotiations for more than two years. Meanwhile, the Gaza Palestinians have been firing rockets at Israeli towns and villages. And on the West Bank, Palestinian President Mahmoud Abbas turns down then-Israeli Prime Minister Ehud Olmert’s offer, walks out of negotiations with Binyamin Netanyahu and now defies the United States by seeking not peace talks but instant statehood — without peace, without recognizing Israel — at the United Nations. And to make unmistakable this spurning of any peace process, Abbas agrees to join the openly genocidal Hamas in a unity government, which even Obama acknowledges makes negotiations impossible.

Obama’s response to this relentless Palestinian intransigence? To reward it — by abandoning the Bush assurances, legitimizing the ’67 borders and refusing to reaffirm America’s rejection of the right of return.

The only remaining question is whether this perverse and ultimately self-defeating policy is born of genuine antipathy toward Israel or of the arrogance of a blundering amateur who refuses to see that he is undermining not just peace but the very possibility of negotiations.