Israel’s test on Wednesday of a new missile able to reach Iran, and the International Atomic Energy Agency’s forthcoming report that exposes the military dimension to Iran’s nuclear program have renewed speculation that Israel’s patience with Obama’s diplomatic efforts to counter Iran’s nuclear program has run out.

Against the backdrop of the crisis, the White House seeks to double down on diplomacy. "What we're focused on is a diplomatic strategy which...increases the pressure on the Iranians, through financial pressure, through economic sanctions, through diplomatic isolation," explained deputy national security adviser Ben Rhodes.

The truth is that while the White House may believe it has still more time for robust diplomacy, but after years of threatening biting sanctions, neither Iran nor Israel believe Obama to be credible.

Add to that differing threat assessments, calculations and the ticking clock of Iranian nuclear developments and there is much that will get in the way of U.S. diplomatic efforts.

The United States, the Europe Union, and Israel may all share concerns regarding Tehran’s nuclear ambitions, but each has remarkably different threat assessments.

For the United States, a nuclear weapons capable Islamic Republic is strategically untenable: A nuclear Iran would set off a cascade of proliferation while Iranian authorities, secure behind their own nuclear deterrent, might launch a terrorist campaign unseen in the region since the 1980s.

For the European Union, Iranian acquisition of nuclear weapons would signal a defeat for Europe’s multilateral philosophy: The Iranian nuclear portfolio, after all, was the first issue outside European borders on which the European Union took the lead. European diplomats wanted to show that they could resolve the Iran crisis through quiet dialogue and with the assistance of international organizations such as the United Nations.

European officials know their failure will be the death knell for the internationalist approach and will provide red meat for Americans who believe that unilateralism is the only effective way to handle rogue regimes.

For Israel, however, the Iranian threat is existential. Israeli officials do not forget that Iranian officials have repeatedly suggested not only that Iran seeks to build a nuclear bomb, but also may use it.

On December 14, 2001, former President Ali Akbar Hashemi Rafsanjani observed, “The use of an atomic bomb against Israel would totally destroy Israel, while the same against the Islamic world would only cause damage.”

On February 14, 2005, Ayatollah Mohammad Baqer Kharrazi, secretary-general of Iranian Hezbollah, declared, "We are able to produce atomic bombs and we will do that,” adding, “The U.S. is not more than a barking dog."

Then, three months later, Gholam Reza Hasani, a confidante of the Supreme Leader, declared possession of nuclear weapons to be one of Iran’s top goals.

Finally, in February 2006, Rooz, an Iranian website close to Iran’s reformist camp, quoted a Qom theologian as saying it was only "natural" for Iran to possess nuclear weapons.

While some American professors say that President Mahmoud Ahmadinejad’s promise to “wipe Israel off the map” was a mistranslation from Persian, they ignore that the Iranian presidency used the phrase in its own English translations, and repeated it on more than two dozen occasions.

The Iranian plot to kill the Saudi ambassador in Washington only adds to Israel’s concern. After all, while Iran experts dismiss the plot as a rogue action, Israeli officials note that the presence of rogue elements within Iran’s Islamic Revolutionary Guard Corps (IRGC) does not bring comfort, especially since it would be the IRGC that would have custody of any Iranian nuclear weapons.

Many military analysts question Israel’s capability to strike unilaterally at Iran’s nuclear facility. Certainly, a strike would be messy and its success uncertain: Iran is much larger than either Iraq or Syria, where Israeli warplanes previously struck at nuclear facilities. Even if Israel went in with surprise, Israeli bombers could not fly out with surprise once they had dropped their bombs. This mandates a wider campaign—one which would target anti-aircraft batteries, command-and-control centers, and perhaps missile batteries and arms caches in third countries through which Iran might retaliate.

Still, analytical concerns that Israel does not have enough bunker-buster bombs to destroy facilities buried deep under mountains are misplaced: Israel needn’t demolish those facilities; it only needs to destroy their entrances.

Likewise, hand-wringing about "unknown" nuclear facilities is misplaced. Should the IRGC rush to defend what previously analysts believed to be merely random mountains, Western intelligence agencies would reap a windfall.

A military strike, however, would not be clean. As I said earlier, it would be messy. There would be collateral damage. Iranians may oppose their leadership, but they are fiercely nationalistic and will rally around the flag. -- I will sell the Brooklyn Bridge to anyone who argues Iranians would welcome bombing. Iran will retaliate.

The tragedy, here, is that this crisis could have been avoided.

While President Obama blamed the Bush administration for the failure of diplomacy, the truth was that Iran’s leadership was never sincere.

On October 24, the Iranian newspaper Etemaad published an interview with Hassan Rowhani, Iran’s chief nuclear negotiator from 2003 to 2005, a period when reformists controlled the presidency. Rowhani admitted that he used diplomacy to run down the nuclear clock. “Two goals become our priority,” he declared, “The first goal was to safeguard the national security, and the second goal was to support and help the nuclear achievements.”

After bragging about how Iran used his period of negotiation to expand its enrichment and heavy water capability, Rowhani explained “The reason for inviting the three European foreign ministers to Tehran…was to make Europe oppose the United States so that the issue was not submitted to the Security Council.”

Obama entered office asking Iran to unclench its fist, and said the United States would not take no for an answer.

Obama may believe his national security successes—killing Usama Bin Laden, Anwar al-Awlaki, and Muammar Qaddafi—immunize him from dealing substantively with Iran until after the 2012 election, but the rest of the world is not willing to operate according to Washington’s political calendar.

Israeli unilateral strikes will be messy and cause immense bloodshed, but Israeli leaders may calculate this to be the least bad option when faced with genocidal leaders on the verge of nuclear weapons capability. Israel believes it faces an existential threat and absent a credible sign that Obama understands that, it will take matters into its own hands.

Michael Rubin is a resident scholar at the American Enterprise Institute and a senior lecturer at the Naval Postgraduate School.