A small but influential group of U.S. lawmakers and former top military officers wants to equip Israel’s air force with some of the biggest and most powerful American-made warplanes—the iconic B-52 and B-1 heavy bombers—plus bunker-busting bombs to go with the planes.

Why? To attack Iran’s nuclear facilities, in case the deal to limit Tehran’s access to atomic weapons collapses. Compared to smaller fighters and attack planes, bombers fly much farther and carry much heavier weaponry, and could do far greater damage to the underground hideouts where Iran stashed much of its nuclear equipment.

But that doesn’t mean Israel wants or needs the giant, complex, and expensive-to-fly aircraft. Not for hitting Iran. Not for anything.

The bomber idea has been pushed by Iran deal foe Tom Cotton and former CIA director David Petraeus, but it originated more than a year ago with David Deptula, a retired U.S. Air Force general who helped plan the air war over Afghanistan in 2001, and Michael Makovsky, CEO of the Jewish Institute for National Security Affairs.

In April 2014, Deptula and Makovsky wrote an op-ed in The Wall Street Journal arguing that the Pentagon should transfer a dozen surplus B-52s to Israel along with a consignment of 15-ton bunker-buster bombs called Massive Ordnance Penentrators. Called MOPs, the bombs reportedly can punch 200 feet underground before exploding, helping them to destroy all but the most deeply buried subterranean facilities.

“It’s time to increase the pressure on Tehran by boosting Israel’s military capacity to cripple Iran’s nuclear program,” Deptula and Makosvky wrote.

The proposal gained momentum as the Obama White House was putting the finishing touches on an agreement with Iran to limit its nuclear program in exchange for a partial lifting of economic and military sanctions. Squeaking through the U.S. Congress, the deal went into effect Oct. 14.

In that light, the Israeli B-52s proposal looks a lot like an attempt by American lawmakers and pundits to undermine the Obama administration’s negotiations with Tehran—or at least to hedge their support among pro-Israeli voters.

In theory, heavy bombers would boost Israel’s ability to strike Iran’s nuclear facilities independently of the U.S. military, lending firepower to opponents of Iran even as the United States officially strikes a deal with the isolated Persian state.

But in practice, the huge planes would probably prove an unnecessary and unaffordable burden to Israel’s small air arm, to say nothing of the geopolitical cost. Israel’s neighbors, many of which have fought wars against the Jewish state, would surely be opposed to it acquiring such heavy weaponry.

U.S. Sen. Tom Cotton, a hawkish Arkansas Republican, is undeterred by the diplomatic implications. “If Israel requests it, I’d be favorably disposed,” Cotton, who chairs the Senate Armed Services committee’s Air Land Power subcommittee, said when Defense News asked him about the bomber idea in early September.

While Cotton’s support for a warplane transfer perhaps isn’t surprising, it’s worth noting that New Jersey Sen. Cory Booker, a Democrat, in September also came out in favor of giving Israel bunker-busters.

Two New York representatives—Democrat Grace Meng and Republican Lee Zeldin—pushed the bombers-for-Israel idea in a May op-ed in the New York Post. “Transferring MOPs to Israel would also help assuage the concerns of Congress and our Middle East allies, who are wary of the emerging deal,” Meng and Zeldin wrote.

Then there are the generals. In an op-ed in The Washington Post in August, retired U.S. Army general and former CIA director David Petraeus and co-writer Dennis Ross, an analyst with the Washington Institute for Near East Policy, endorsed the idea of equipping Israel with the MOP bomb “and the means to carry it.”

“While some may question whether we would act militarily if the Iranians were to dash to a bomb, no one questions whether the Israelis would do so,” Petraeus and Ross wrote. Loose translation: We have to give bombers to Israel because President Obama is too weak to ever send in America’s own bombers.

“The option for Israel to obtain long-range, high-payload aircraft is one that should be considered in the light of a variety of considerations,” Deptula told The Daily Beast. Namely, the world is too scary not to give bombers to Israel. “Evolving geopolitical conditions that are rapidly growing in complexity call for considering options beyond the status quo, or incremental changes to security postures.”

Indeed, adding bombers to its arsenal would be anything but “incremental” for Israel. Bombers are a big deal.

A B-52—the U.S. Air Force operates 76 of the eight-engine planes and keeps others in mothballs—costs $70,000 per hour of flight for fuel, spare parts, etc. A four-engine B-1, of which the Air Force has 60 in service plus another 30 or so in storage, costs $58,000 an hour. In a typical year of training and combat, a bomber might rack up 200 hours in the air, meaning a single B-52 can run up a $14 million annual tab.

While the $100 billion-a-year U.S. Air Force might be able to afford such extravagance, the much smaller Israeli air force surely can’t. The entire annual Israeli defense budget—for the army, navy, and air force—is about $15 billion.

Even Cotton has acknowledged the money is a problem. “Whether it’s B-52 or B-1, we know Israel’s military would need to expand its infrastructure,” the senator said. “There are real questions about long-term life-cycle costs of a long-range bomber and whether that’s an investment Israel wants to make.”

The Israelis use F-16s ($22,000 per flight hour) and F-15s ($42,000) for ground-attack missions—and even sent these planes on daring, long-distance raids to destroy nuclear facilities in Iraq and Syria in 1981 and 2007, respectively. Israel doesn’t actually need American-made bombers to damage Iran’s nuke facilities—although, to be fair, some of Iran’s nuclear labs are deeply buried and probably impervious to smaller bombs.

Indeed, on Oct. 12, the Iranian Revolutionary Guard Corps, Iran’s most hardline military branch, invited pro-government Iranian reporters to tour an underground missile base that the IRGC claimed lies 500 meters underground—much deeper than even a MOP can penetrate.

To contend with such deeply buried bunkers, the U.S. Air Force trains bomber crews to aim for the vulnerable doorways or even for the above-ground vents that pump fresh air underground.

A B-52 hauling a 15-ton MOP bomb could, in theory, wipe out most underground facilities and inflict serious damage on the others, thus impairing if not halting Tehran’s nuclear program. But then, so could a computer virus—and unlike a 200-ton bomber, computer viruses can be untraceable. In 2010, a sophisticated malware called Stuxnet wreaked havoc on computer-controlled Iranian centrifuges, which are vital to enriching uranium for an atomic bomb.

In a world with Stuxnet, a B-52 in some ways is a costly redundancy. And worse, a bomber can do a lot of other things besides hit atomic labs. Indeed, Israeli bombers would pose a threat to all of the Jewish state’s rivals and could badly upset the Middle East balance of power. If Israel got heavy bombers, it would be the only country besides the United States, Russia, and China to operate such planes.

But then, practicality and stability were never the main concerns of the pols and retired generals pushing the bombers-for-Israel idea. “I think it’s posturing all the way down,” said Dr. Robert Farley, a University of Kentucky professor and author of Grounded: The Case for Abolishing the United States Air Force.

Farley has written extensively about the Israeli-bomber scheme. “For Booker and other Dems, this is a convenient way to display pro-Israel cred while still voting for the Iran deal,” Farley said. “For the GOP, it’s another tool to hit Obama and congressional Dems with.”

Deptula maintains that sending surplus American bombers to Israel is a serious proposal. “Ultimately, Israel will have to make that decision for itself,” he said.

But Israel has made the decision—by alternately ignoring and rebuffing the bomber overtures for a year and a half. Current Israeli military leaders haven’t officially commented on the proposal, but former leaders have made it clear the tiny country’s modest air arm, whose biggest frontline warplanes are fighter jets, can’t accommodate entire squadrons of giant bombers.

“Intuitively, I don’t believe this is the right answer or even relevant to the Israel air force,” Giora Romm, a retired deputy commander of the Israel air force, told Haaretz. “It’s like buying a pair of shoes many sizes too large.”

“It is way beyond our means [and] not worth the means, money, and effort,” an unnamed senior Israeli officer told Al-Monitor. “We are not capable of maintaining and sustaining it.”

“This idea is irrelevant for Israel,” the officer added.

But then, for American advocates of sending bombers and giant bombs to Israel, the idea was never actually about Israel.