The US military has developed new strike plans that include potentially using the so-called “mother of all bombs” to target Iranian energy infrastructure and nuclear sites should President Donald Trump give the order to resume combat operations either before or after the midterm elections, according to multiple US officials familiar with the matter.

Using the GBU-43/B Massive Ordnance Air Blast Bomb or MOAB, the largest non-nuclear bomb in the US arsenal, for the first time in the conflict with Iran would mark a notable escalation, even though there are doubts over how effective it would be in accomplishing any of Trump’s stated strategic objectives or tipping the balance of the war, multiple sources familiar with internal military planning discussions about potentially deploying the weapon said.

Trump is facing pressure to bring an end to the deeply unpopular war — as Republicans brace for potential political backlash from voters in the upcoming midterm elections and there is little indication the two countries are close to a negotiated resolution after more than six months of US bombing.

While the US military continues to provide Trump with options for potential strikes against outstanding Iranian targets, some officials continue to privately question whether the White House has a strategy that incorporates those plans in a way that could actually end the war — something only the president has the power to do.

For months, Trump and his advisers have discussed options that could act as a “definitive” end to the war, at least from a messaging point of view, aware of how unpopular the conflict has become among Americans.

While some administration figures have characterized the war as essentially won, Trump has been more guarded in recent remarks, stopping short of declaring victory and saying the US still has unfinished business in the country.

Behind the scenes, Trump has also cast doubt on some outside allies who have encouraged him to simply bring US troops home and move on. Doing so, Trump has argued, would look like defeat.

Over the course of the last several weeks, White House advisers have held meetings to discuss various options for Iran. While Trump announced publicly that he would not take new actions before the midterms, several advisers said privately they didn’t know whether that statement was definitive or could change before Election Day.

Trump has ordered the military to develop additional strike packages against Iranian targets that include “a lot of energy infrastructure” and the potential use of a MOAB, one of the sources told CNN. The same source said the phrasing used was that this attack would come “prior to US retrograde in CENTCOM AOR (area of responsibility),” indicating the administration could launch the additional strikes, attempt to declare victory and quickly pull everyone out.

A second source told CNN that military plans for striking Iranian nuclear sites, including Pickaxe Mountain, also explicitly call for using the MOAB. In recent months, Trump has repeatedly threatened to strike Pickaxe, where the US and Israel believe Tehran has stored components of its nuclear program, even after pausing full combat operations earlier this year, and Trump continues to emphasize that his goal is to ensure Iran never obtains a nuclear weapon.

Another US official noted that when the military plans, it develops a menu of options for policymakers that range from the high-end to low-end. Higher-end targets, including those that are located deep underground, require bigger bombs, and the MOAB is the biggest, the official added.

But there are questions around whether the MOAB would be an effective munition to use against Iran’s nuclear facilities and other sites that are located deep underground. While the GPS-guided bomb is capable of destroying an area equivalent to nine city blocks, it likely lacks the capability to penetrate deep enough under the surface to destroy the suspected nuclear facilities at Pickaxe, which is believed to be fortified by layers of granite, and other remaining Iranian nuclear sites, sources said.

“The MOAB is a massive information operation type weapon that is great for huge area clearance but not much else,” a third source familiar with military planning discussions around Iran told CNN. “It is definitely not designed as a deep penetration warhead.”If used, the MOAB would have devastating effects on the area that it impacts but likely only at the surface level, the sources noted. And the bomb’s massive blast radius would almost certainly raise concerns about the prospect of civilian casualties — particularly if it is used to target Iranian infrastructure targets located near populated areas and in close proximity to non-military sites.

Still, Trump could opt to use the MOAB as a psychological weapon at a time when the Iranian regime appears dug in and unwilling to bend to his diplomatic demands. While US officials warn that deploying it is unlikely to force Iran’s capitulation or achieve a strategic military victory — it could provide Trump with an additional option, short of restarting full combat operations, to alter the conflict’s current status quo.

“POTUS has unfortunately put himself in a situation where he is almost compelled to do something and, without the ammunition designed to penetrate that level … you have to look at psychological effects for which the MOAB is well-equipped,” the third source familiar with recent planning discussions added.

Many within the administration as well as outside analysts agree that the only way to decisively defeat Iran would be through a major operation involving ground troops, a commitment that could potentially cost thousands of American lives. The Pentagon considers all scenarios, so those plans exist, but as of now no one in the administration is arguing for such drastic action.

Trump has indicated he has little interest in putting US boots on the ground in Iran but his desire to end the conflict as soon as possible presents a political dilemma for a president who is keenly aware of how unpopular the war has become yet has been unable to secure a diplomatic agreement that would bring it to a close.

Top Trump administration officials and military planners have been focused, for weeks, on finding an off-ramp that gives Trump a “symbolic” win — at minimum — he can try to sell to the American people without preventing a potential diplomatic breakthrough, starting with an agreement to reopen the Strait of Hormuz, CNN has reported.

A fourth source familiar with the Pentagon’s recent planning discussions on Iran told CNN that military officials had developed some options that would amount to a “fireworks show,” with the goal of providing Trump an off-ramp from the conflict even if those strikes fail to accomplish his stated goals for starting the war in the first place.

And despite Trump’s recent pledge to hold off on launching additional strikes before the midterms, the US military already appears to be preparing for potential Iranian retaliation should the president give the go-order.

The next turnover of US troops deployed to CENTCOM is also expected to take place within the next few weeks, according to a fifth source, a US official who acknowledged it is possible some of the personnel who rotate out of the region, may not be replaced by fresh service members.

Asked about the plans, a White House official told CNN that they do not comment on sensitive military plans that may or may not exist, adding “President Trump keeps all options on the table to ensure that Iran can never have a nuclear weapon.”

In response to CNN’s request for comment, a Pentagon official said: “The Department of War plans for a wide range of operational scenarios to execute Presidential and Secretary‑level direction and to ensure mission success in any operational environment.”

Developed during the Iraq War, the MOAB is an air blast-type warhead that explodes before hitting the ground to project a massive explosion from all sides.

During the final stages of testing in 2003, military officials told CNN the MOAB was mainly conceived as a weapon employed for “psychological operations.”Military officials said then they hoped such a huge blast would rattle Iraqi troops and pressure them into surrendering or not even fighting.

As originally conceived, the MOAB was to be used against large formations of troops and equipment or hardened above-ground bunkers. The target set has been expanded to include targets buried under softer surfaces, such as caves or tunnels.

Trump was the first US president to deploy the MOAB, during his first term when he authorized the military to use its most powerful non-nuclear bomb on ISIS positions in Afghanistan in 2017.

That strike targeted a network of fortified underground tunnels that ISIS had been using to stage attacks on government forces — killing 36 ISIS fighters, Afghan officials said. The blast destroyed three underground tunnels as well as weapons and ammunition, but no civilians were hurt, Afghan and US officials added at the time.

At the time, the bombing marked a dramatic change in attitude for Trump, who advocated an isolationist, “America first” foreign policy during his first election campaign.

Following the 2017 strike, US military officials were pressed on whether the 21,600-pound bomb was necessary for that particular target and would likely face similar questions if the munition is deployed against Iran.