The United States has confirmed the use of multiple 5,000-pound deep-penetration munitions against hardened Iranian missile sites near the Strait of Hormuz, in what appears to be a significant escalation in the current war and a notable development in the use of American conventional bunker-busting weapons.

According to US Central Command, the targets were fortified coastal missile positions whose anti-ship systems posed a threat to international shipping in the strait.

Hours ago, U.S. forces successfully employed multiple 5,000-pound deep penetrator munitions on hardened Iranian missile sites along Iran’s coastline near the Strait of Hormuz. The Iranian anti-ship cruise missiles in these sites posed a risk to international shipping in the… pic.twitter.com/hgCSFH0cqO

— U.S. Central Command (@CENTCOM) March 17, 2026

The strike is drawing particular attention because defence reporting has identified the weapon involved as the GBU-72, the Air Force’s newer 5,000-pound-class penetrator designed for hardened and deeply buried targets. While US officials have publicly referred only to “deep penetrator munitions”, specialist reporting and Pentagon-focused coverage have linked the operation to the GBU-72, a weapon developed to improve on the older GBU-28 and tested by the US Air Force in 2021. The Air Force has said the GBU-72 was created specifically to overcome hardened, deeply buried target challenges and was designed for use by both fighter aircraft and bombers.

That matters because the Iranian sites targeted near Hormuz were not ordinary missile batteries. They were described as hardened positions along Iran’s coastline, intended to support anti-ship operations in one of the world’s most sensitive maritime choke points. The Strait of Hormuz remains critical to global energy markets, and military action around it has immediate international consequences. Reuters reported last week that the Trump administration had already claimed to have struck military targets on Kharg Island, while broader fighting has left the strait under sustained pressure and shipping exposed to Iranian missiles, drones and mines.

The importance of the latest strike therefore lies less in the dramatic language circulating on social media than in the military signal it sends. The United States is showing that it is prepared to attack fortified and buried infrastructure, not merely surface launchers or mobile assets. That suggests a shift towards systematically dismantling Iran’s ability to sustain anti-shipping operations from protected underground facilities rather than simply degrading them temporarily.

There is, however, a need for caution about some of the wider claims now being made around the strike. It has not been officially confirmed that the GBU-72 was used for the first time in combat, even though several reports describe it that way. Nor has Washington publicly identified the aircraft that carried the bombs. The B-1B Lancer is frequently mentioned because of its heavy conventional payload, officially listed by the US Air Force at 75,000 pounds, but no formal statement has confirmed that platform’s role in this particular mission.

What is clear is that the strike forms part of a broader campaign. On 19 March, Reuters reported that the Israeli military said it had carried out strikes on Iranian naval infrastructure in the Caspian Sea, claiming to have hit a military port where dozens of vessels were docked. That came as the maritime dimension of the war continued to widen beyond the immediate waters of the Gulf.

At the same time, the conflict has expanded into the energy sector with growing effect on global markets. Israeli strike on Iran’s South Pars gas field was followed by Iranian retaliation against Gulf energy infrastructure, including Qatar’s Ras Laffan complex. European gas prices rose by as much as 35 per cent on Thursday, while Brent crude briefly climbed above $119 a barrel before retreating. EU receives around 9 per cent of its LNG from Qatar. Dutch TTF gas prices had doubled since the war began on 28 February, reaching €74 per megawatt hour on 19 March.

In that wider context, the US strike on buried missile sites near Hormuz is not just a tactical episode. It reflects an effort to remove the systems most directly associated with Iran’s threat to maritime traffic and energy flows. If the GBU-72 was indeed the weapon used, the operation would also illustrate how the US is bringing newer conventional strike capabilities into active combat against deeply protected targets.

What remains uncertain is how far this campaign will go. There is ample evidence of a broader US-Israeli effort to degrade Iran’s military and logistical infrastructure. There is not yet firm public evidence for some of the more sweeping claims circulating online about total destruction, confirmed platform details, or imminent ground operations. For now, the confirmed facts are serious enough: Washington has struck hardened Iranian missile positions near Hormuz with 5,000-pound penetrator munitions, and the conflict is increasingly shaping both military doctrine and global energy risk in real time.