John Kerry began the year trying to bring representatives of the Assad regime together with rebel leaders in Geneva to end the civil war in Syria.

It was bound to fail. It failed. Strike one.

Next, the secretary of state worked tirelessly to create a framework agreement between Israelis and Palestinians, with a view to settling their differences once and for all.

It was bound to fail. It failed. Strike two.

This week, U.S. negotiators and their counterparts from the P5+1—the five permanent members of the Security Council, plus Germany—will meet in Vienna with Iranian negotiators to work out the details of a final nuclear agreement.

You know where this is going.

There's been a buzz about these negotiations, with Western diplomats extolling the unfussy way their Iranian counterparts have approached the talks. Positions are said to be converging; technical solutions on subjects like the plutonium reactor in Arak are being discussed. Last month Iranian Foreign Minister Mohamad Javad Zarif said there was "50 to 60 percent agreement."

All this is supposed to bode well for a deal to be concluded by the July deadline. If the Iranians are wise, they'll take whatever is on the table and give Mr. Kerry the diplomatic win he so desperately wants. Time is on Tehran's side. It can sweeten the terms of the agreement later on—including the further lifting of sanctions—through the usual two-step of provocation and negotiation.

The only thing Iran has to fear is an Israeli military strike. For that to happen, Jerusalem needs (or believes it needs) conditions that are both militarily and diplomatically permissive. By agreeing to a deal, the Iranians further restrict Israel's options without permanently restricting their own.

But Iran is not wise. It is merely cunning. And fanatical. Also greedy, thanks to a long history of being deceitful and obstreperous and still getting its way without having to pay a serious price. So it will allow this round of negotiations to fail and bargain instead for an extension of the current interim agreement. It will get the extension and then play for time again. There will never be a final deal.

Why am I so confident? Listen to the man with the last word first: "They expect us to limit our missile program while they constantly threaten Iran with military action," Supreme Leader Ali Khamenei said Sunday. "So this is a stupid, idiotic expectation. The Revolutionary Guards should definitely carry out their program and not be satisfied with the present level. They should mass produce."

Ballistic missiles are lousy weapons for anything except the rapid delivery of chemical or nuclear warheads. (The 39 Iraqi Scuds that hit Israel in 1991 killed two people.) But limiting the number and range of ballistic missiles is central to any agreement that aims to prevent Iran from having a rapid nuclear-breakout capability. Mr. Khamenei's public call to mass produce missiles is not exactly an indication of seriousness about a final deal.

Also a sign of non-seriousness was last month's call by Ali Akbar Salehi, head of Iran's Atomic Energy Organization, to add an additional 30,000 centrifuges to Iran's existing 19,000. "So far we have produced seven to eight tons of enriched uranium," he said. But he wants Iran to produce 30 tons, ostensibly to fuel the civilian nuclear plant at Bushehr. And that's 30 tons a year. A single ton of civilian-grade uranium suffices, with further enrichment, for a single atomic bomb.

Still not getting the drift? "Iran will not retreat one step in the field of nuclear technology," said one prominent Iranian over the weekend. "We have nothing to put on the table and offer to them but transparency. That's it. Our nuclear technology is not up for negotiation."

That's Iranian President Hasan Rouhani speaking. For good measure, he added that Iran would go back to producing 20% enriched uranium—which is close to weapon-grade—"whenever necessary." And he's the moderate. Even the Obama administration cannot accept a deal that allows Iran to expand its centrifuge capabilities or enrich uranium to 20%.

The hardening of Tehran's negotiating position is another reminder of the blunder the administration made when it agreed to the interim deal and then turned on Congress to prevent automatic sanctions in the event Iran failed to make a final deal. "Show that you are strong, and you will see results"—such was the advice Mr. Rouhani confidentially offered an Israeli agent posing as a U.S. official in 1986 on how to deal with the Ayatollah Khomeini. The advice is still sound.

In the meantime, the administration needs to think about what it will do when Mr. Kerry strikes out. Is there a Plan B, other than the president's now trademark mix of hollow threats and soliloquies on the limits of presidential power? I doubt it. Goethe wrote that nothing is worse than aggressive stupidity, which is true. But pompous impotence surely comes in second place, and this administration combines aspects of both.

The Israelis may sit still through all this. But Mr. Kerry shouldn't count on it.