Current American relations with our once-staunch ally Israel are at their lowest ebb in the last 50 years.

The Obama administration seems as angry at the building of Jewish apartments in Jerusalem as it is intent on reaching out to Iran and Syria, Israel's mortal enemies. President Obama himself, according to reports, has serially snubbed Israeli Prime Minister Benjamin Netanyahu. A new narrative abounds in Washington that Israel's intransigence with its Arab neighbors now even endangers U.S. troops stationed in the Middle East. Obama is pushing Netanyahu's Likud government to make concessions on several fronts, from supplying power and food to Gaza, to hastened departure from the West Bank.

These tensions follow the Obama administration's new outreach to the Muslim world. Obama gave his first interview as president to the Middle East newspaper Al Arabiya, in which he politely chided past U.S. policy on the Middle East.

In his June 2009 Cairo address, the president again sought to placate the Islamic world — in part by wrongly claiming that Islamic learning had sparked the European Renaissance and Enlightenment.

Lost in all this reset-button diplomacy is introspection on why past American presidents sought to support Israel in the first place. We seem to forget why no-nonsense Harry Truman, against worldwide opposition, ensured the original creation of the Jewish state — or why more than 60 percent of Americans in most polls continue to side with Israel in its struggle to survive.

In contrast, most of the rest of the world does the math and concludes Israel is a bad investment. It has no oil; its enemies possess nearly half the world's reserves.

There is no downside in criticizing Israel, but censuring some of its radical Arab neighbors might prompt anything from an oil embargo to a terrorist response.

No wonder that in the ongoing dispute, most of the world adds up the pluses and minuses and concludes that it is wiser to side with Israel's foes than to become its friend. But why, until now, has America always bucked the tide?

The reason is not the so-called "Jewish lobby" here in the U.S., but because a clear majority of non-Jews supported Israel. They saw that in a sea of autocracy, Israel is a democracy and a free and open society, one quite different from its neighbors.

I suspect that when there is a final two-state settlement, Arabs wishing to remain inside Israel will be treated far more humanely as citizens than any Jews who stay on the West Bank and take their chances as residents of the new Palestinian state. We suspect that when Israel pulls back from lands occupied after the 1967 war, there will remain prominent calls in the Arab world to continue the withdrawal — and finish Israel altogether.

Holocaust denial is still a staple in intellectual circles of the Middle East, and serially embraced by the Iranian government.

Nearly a third of all country-specific resolutions passed by United Nations Commission on Human Rights have damned Israel — far more than anything directed at the mass-murdering regimes of Idi Amin, Pol Pot, Saddam Hussein or the Taliban.

In contrast, America's traditional bipartisan support for Israel put the world on notice that the United States would never allow another Holocaust — or the destruction of Israel, or even serial attacks against it.

Yet if we are seen as neutral, just watch the rest of the world get the message and start piling on. Frontline entities like Hez-bollah, Syria and Iran will ready their missiles without worry of American anger. Iran will assume we are resigned to its acquisition of the bomb. And the UN will again begin providing cover by issuing its pro forma denunciations of Israel, counting on a newly diffident United States to vote "present."

Perhaps the Obama administration genuinely believes that by pressuring Israel and reaching out to its enemies, it can at last achieve peace. Perhaps a few key figures in this administration simply do not like or trust the Jewish state — support for which now polls only 48 percent among Democratic voters (versus 85 percent among Republicans).

No matter. This administration should take a deep breath and review history. It would learn that when Israel is alone, its opportunistic enemies pile on. And then war becomes more, not less, likely.