Donald Trump and Benjamin Netanyahu believed that victory over Iran would reshape the Middle East.
The region is being reshaped. But not in the way they expected. The Islamic Republic of Iran has not been defeated. The risk now is of a long, attritional permacrisis that will lurch in and out of outright conflict.
The Iranian regime has proved to be a much harder nut to crack than Trump and Netanyahu had assumed. Their judgement was wrong, and they have lost control of the consequences.
The latest of those is Iran's downing of the US Apache helicopter. It is another reminder that Iran's rulers can still hurt the Americans and will not budge in their determination to come out of this war on top. For them, victory equals survival and enhanced deterrence, in the shape of acknowledgement of their control of the Strait of Hormuz, one of the world's most strategic waterways.
The president and his generals will try to calibrate their response to the loss of the helicopter, to show just as emphatically that they cannot be pushed around, but at the same time to preserve the sluggish and so far unproductive diplomatic process. The Apache's crew survived. Had they been killed, a much harsher response would have been likely.
Trump has been banking on a deal with Iran to reopen the Strait of Hormuz and agree the terms of much longer-term talks over the big issues, starting with Iran's stockpile of enriched uranium and its wider nuclear plans.
The war is unpopular in America and he wants a way out he can present as a victory. It is proving to be a tough challenge.
Trump and Israel's Prime Minister Benjamin Netanyau are learning an old lesson.
Ever since humans discovered the art and curse of war, leaders have found out that it is easier to start a war than to end one with a clear victory.
When they led their countries to war with Iran on the last day of February, both issued video statements, choosing words that reflected an assumption that a moment of historical change was coming. The regime that had ruled Iran since the Shah was overthrown in 1979 was on the way out.
In the small hours of the morning at Mar-a-Lago, his Florida resort, Trump, picked up on the promise he had made to Iranian opponents of the regime in January that "help is on its way."
"To the great proud people of Iran, I say tonight that the hour of your freedom is at hand. Stay sheltered. Don't leave your home. It's very dangerous outside. Bombs will be dropping everywhere. When we are finished, take over your government. It will be yours to take. This will be probably your only chance for generations."
The next morning, Netanyahu stood in the sunlight on the roof of the Kyria, Israel's high rise defence ministry in central Tel Aviv, to record his address. Like Trump, he spoke as if victory was certain.
"This coalition of forces allows us to do what I have yearned to do for 40 years: smite the terror regime hip and thigh. This is what I promised – and this is what we shall do."
Throughout his political life, Netanyahu has argued that the real threat to Israel comes from Iran, not from the Palestinians or his country's Arab neighbours. He had tried and failed to get other American presidents to join him in attacking Iran. Trump was different.
For more than two years, since Hamas attacked Israel on 7 October 2023, Netanyahu had told Israelis that the power of their military, backed by America, would vanquish their enemies and usher in a richer and safer future. Force, not diplomacy, was the answer.
Netanyahu had the air of a man whose moment had come. In contrast, when he faced the cameras after Trump told him to cancel his plans to attack Beirut on Monday, the leading Israeli newspaper columnist Ben Caspit said he looked like a deflated balloon.
Caspit is one of the prime minister's most vociferous critics. But it is clear that Netanyahu's strategy of using force to bend the region to his will has failed.
Trump expected a quick victory. He had watched with delight as the US military abducted the president of Venezuela and his wife, sent them to a jail in New York and installed a compliant successor in Caracas. Textbook regime change, he believed, way better than the forever wars fought by his predecessors in Iraq and Afghanistan. Iran would be next on the list.
Both men must be wondering what went wrong. The United States has the world's most powerful military. Israel is the superpower of the Middle East.
Trump and Netanyahu saw a regime in Tehran reeling from economic crisis caused by sanctions, mismanagement and corruption. Israel had delivered hammer blows to its allies, Hamas in Gaza and Hezbollah in Lebanon. Its other key ally, Bashar al Assad had been deposed as president of Syria and fled to Moscow. In January the regime crushed huge demonstrations against it by killing thousands of Iranian citizens.
They underestimated the resilience, ruthlessness and guile of the Islamic regime. They believed that killing its supreme leader and his closest lieutenants would cause the regime to collapse from within.
They overestimated the efficacy of military force against a regime that had faced repeated threats for almost 50 years, had engineered itself to survive an attack and had thought hard about a conception of national security backed up by its religious and ideological convictions.
The Gulf oil states, allies of the US, and in the case of the UAE and Bahrain of Israel too, have suffered hammer blows. It is not simply lost revenue from petrochemicals and their byproducts, like fertiliser. They have built their futures around creating an oasis of stability and multi-billion-dollar business in the Gulf. Potential investors, and tourists, see the war turning that vision into a mirage.
The Iranian regime believes its survival and the ease with which it put a chokehold on the world economy by closing the Strait of Hormuz and attacking its Gulf Arab neighbours can be translated into long-term deterrence against the US and Israel.
The men who have replaced the old guard of Iranian leaders killed by Israel and the US are just as ideological as their predecessors but much more willing to take risks in what they see as an existential struggle. They believe that words alone will not stop more attacks in the future from the US or Israel. Instead, they want to demonstrate that more attacks on Iran will lead to painful consequences.
A key part of its strategy is linking the war in Lebanon with the war in the Gulf. The regime's message to Trump is that he cannot hope for any kind of deal if Israel continues to bomb Lebanon and to try to destroy Hezbollah, the militia and political movement that it has nurtured since the 1980s as its forward defence against Israel.
By curbing Israel's plans to attack Beirut, on the grounds that a deal was near (a claim he has made before, erroneously), Trump has shown implicitly that he accepts the link between what happens in Lebanon and what happens in the Gulf.
On Monday, Netanyahu said he would not accept the linkage. It was he said, "intolerable and completely unacceptable." His problem is that Trump will put his interests and desire to end the war ahead of Netanyahu's determination for it to continue until he can declare the Islamic regime in Tehran has been crippled.
Netanyahu cancelled a planned attack on Beirut, but since then Israel's military, the IDF, has continued to hit southern Lebanon very hard.
When the Strait of Hormuz was closed in March, there were dire warnings of global economic consequences if it was still closed by June.
Not only does the vital waterway that was open until the US and Israel attacked Iran remain closed. Without remarkable diplomatic breakthroughs, it is hard to see it reopening any time soon.
