Support for Israel doesn’t mean accepting its misguided policies.

It has never been a secret that the United States pays a steep price in the Muslim world for being Israel's staunchest ally. But when a U.S. official actually says so, as Gen. David Petraeus did during a Senate hearing last month, it's a sure sign that tension between the allies is rising. And so it has, reaching a peak not seen in some time.

Petraeus, who is responsible for managing the wars in Iraq and Afghanistan, was appropriately blunt. The Arab-Israeli conflict "foments anti-American sentiment" because of the "perception of U.S. favoritism for Israel," he told the Senate. Anger at Israel and the U.S. undercuts moderate Arab regimes and gives al-Qaeda a potent recruiting tool.

Vice President Biden reportedly said the same thing in a private meeting with Israeli Prime Minister Benjamin Netanyahu in Israel a week earlier, when the Israelis picked the occasion of Biden's visit to announce that they would build 1,600 more housing units in a disputed part of Jerusalem

Though Biden's staff later denied he said it, Israel's largest daily paper, Yediot Aharonot, quoted the furious vice president as telling Netanyahu, "This is starting to get dangerous for us. What you're doing here undermines the security of our troops who are fighting in Iraq, Afghanistan and Pakistan."

Biden accepted Netanyahu's apology for the poor timing, but a seething President Obama arranged for Secretary of State Hillary Clinton to dress down Netanyahu in a scathing 43-minute phone call. Obama reinforced the point in an unusually frosty meeting when Netanyahu came to Washington 10 days later.

Fighting publicly with a close friend over intolerable behavior is always ugly. But a frank discussion is unavoidable if the administration is to have any hope of getting the two countries' interests aligned.

This isn't an argument over whether the U.S. should support Israel. It should, for any number of reasons, not the least of which is that the Jewish state is a beacon of democracy in a vital region. It is a question of whether doing so requires the U.S. to blindly accept every Israeli action, no matter how provocative, unnecessary for the country's security or contrary to U.S. goals.

Further expansion of settlements into the potential territory of a future Palestinian state is objectionable on all three counts. More so in Jerusalem, which both sides see as holy and claim as their capital.

This isn't to excuse the Palestinians, who have consistently undermined the peace process, turned down serious U.S.-brokered peace offers in 2000 and 2008, launched attacks from Hamas-controlled Gaza, and currently refuse to talk directly with the Israelis. To an extent, U.S. impatience with Israel emboldens the Palestinians to be even more obdurate.

But their blundering is not cause for the Israelis to deliver a gratuitous poke in the eye, particularly one that undercuts Palestinian moderates and damages U.S. interests.

Supporting Israel will never be costless or risk-free. But this country should expect the Israelis not to act in ways that make it even harder and more dangerous to be their friend.

Public backing for Israel is strong in the U.S. — 63% in the most recent Gallup poll. But if Americans whose own family members' lives are at risk every day in Iraq and Afghanistan come to believe that Israel's actions needlessly increase that risk, support would be jeopardized. The administration is right to warn the Israelis of that danger.