Labor Party leader Isaac Herzog and Prime Minister Benjamin Netanyahu in the Knesset in January 2014Ariel Schalit/AP

The Israeli prime minister, Benjamin Netanyahu, spent part of his weekend appearing on American news shows, denouncing the framework nuclear agreement between Iran and six world powers. "I'm not trying to kill any deal. I'm trying to kill a bad deal," Netanyahu told Chuck Todd on Meet the Press.

Netanyahu will most likely fail in his attempt to kill the deal, assuming Iran can bring itself to sign off on its still-undecided requirements (right now, the deal is much more "framework" than "agreement"). It is difficult for a small country, even one backed by Sheldon Adelson, to defeat a superpower. And it is very difficult to go up against a president who believes, as Barack Obama apparently does, that the Iran deal may be his signature foreign-policy achievement.

Unlike Amir Oren, who argues in Haaretz that Netanyahu's campaign against the Iranian nuclear program has been an "absolute failure," I believe Netanyahu's 10-plus-year campaign to highlight Iran's nuclear ambitions has usefully concentrated world attention—and President Obama's attention—on the need to counter its program. But Netanyahu's goal now is both unrealistic and destructive to Israel and its relationship with the United States. He has already done great damage to his country's relationship with the Democratic Party by playing so obvious a partisan game.

If Netanyahu would only move away from his maximalist goal of spiking the deal and think instead about shaping the deal in ways that could meet many of Israel's needs, he would have a much greater chance of success. However, in order to do this, he needs a domestic partner. He himself has close to zero credibility in the White House, which sees him as a political adversary on par with John Boehner. The officials around him—among others, his ambassador to the U.S., Ron Dermer; his current defense minister, Moshe Ya'alon; the man who may be the next defense minister, Naftali Bennett—have no credibility with the Obama administration either.

Someone who has credibility, however, is Isaac Herzog, whose Zionist Camp party received the second-highest number of votes in the recent Israeli election. As Aluf Benn argues in a very smart column, Israel is facing such acute challenges on the Iran front—and on the American front—that it cannot afford to send officials to Washington who will be ignored. Herzog would not be ignored, which is why a national-unity government makes sense. Here's Benn:

The guiding principle in [Netanyahu's] efforts to form a government should be the national interest, not power struggles on the right. Timing is critical. The framework deal has changed the balance of power in the region, challenging U.S.-Israel relations. A unity government is the correct way of contending with these changes. A right-wing government will only enhance Israel’s isolation and weaken it vis a vis Iran and no fiery speech by Netanyahu can prevent this from happening. That can only be achieved by a government that projects political moderation.

Herzog and Netanyahu are not as divided on the Iran issue as one might think; Herzog holds down the right flank in his home party, Labor, and Netanyahu—believe it or not—holds down the left in the Likud (a Likud leftist being defined today as someone who still comprehends basic geopolitical reality, particularly as it relates to America's indispensable role in Israel's security). Herzog would do a better job than any official in a narrow-right coalition of making Israel's case for a tougher, more foolproof final Iran deal. And Israel has legitimate worries. Again, Benn:

Israel has several important demands to make of the U.S. administration. Firstly and above all, Israel’s nuclear capabilities and deterrence must be maintained, and a guarantee that any regional or international initiatives to impose a nuclear agreement on Israel that would restrain its power would be foiled. Iran will probably demand that the reactor in Dimona also be placed under strict limitations and supervision in the arrangements that are hammered out, just as will be the case for the facilities in Natanz, Fordow and Arak. The United States must protect Israel from such a demand.

The second demand must be to strengthen the conventional capabilities of the Israel Defense Forces, including funding the setting up of the David’s Sling (Magic Wand) missile system, which was successfully tested last week. The system is designed to afford protection from Hezbollah missiles. Further financing is required for Iron Dome batteries, for protection against short-range missiles and for the Arrow 3 system, designed to protect against Iranian surface-to-surface missiles. Also required are a strengthening of intelligence-gathering capabilities and more long-range unmanned aerial vehicles, and possibly a squadron of F-35 fighters, so beloved of Israel’s Air Force commanders.

It seems fairly obvious that if Netanyahu indeed believes that Iran poses a unique threat to Israel's survival, then he would seek to have the most effective advocate for Israel making the country's case in the place it matters most: the White House.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.