Iran puts Europe on notice with ‘game changer’ Diego Garcia missile incident

Iran’s firing of two missiles toward the joint U.S.-U.K. base in the Indian Ocean is putting Europe on notice that Tehran appears able to levy attacks previously considered beyond its reach. 

In the March 20 incident, one intermediate-range ballistic missile fell into the water and the other was shot at.

Still, while unsuccessful, it attests to a long-held belief by national security officials that Iran’s agreement to the self-imposed range ceiling of 1,240 miles on its missiles is a political, not a technical cap and that Tehran could pose a danger far beyond its borders. 

Analysts said it should force Western officials to rethink some of the underlying assumptions about Iran’s missile threat and how far Tehran could reach if left unchallenged. 

“While America has been defanging its missile program, an entirely new missile has been, in essence, revealed, and that is a game changer,” said Behnam Ben Taleblu, a senior director of the Foundation for Defense of Democracies (FDD) Iran Program.

He noted that Europe would be in striking distance “if Iran even develops an IRBM, an intermediate range ballistic missile, rather than an intercontinental ballistic missile, which is what the regime would need to target the U.S. homeland.”

Nicholas Carl, a fellow with the Critical Threats Project at the American Enterprise Institute (AEI), said in a recent interview that “we now need to, I think, rethink some of the underlying assumptions people have long had about the Iranian missile threat and where Iran could plausibly reach.” 

Hudson Institute senior fellow Can Kasapoğlu said Iran has for years maintained the “convenient fiction” that its missiles had a self-directed range of 1,240 miles, serving its diplomatic interests while “masking the true pace of its development” program.

“That fiction is now operationally obsolete. A strike profile extending into the Indian Ocean demonstrates not merely extended range, but Iran’s deliberate abandonment of strategic ambiguity,” Kasapoğlu wrote in his analysis. “Iran is no longer signaling restraint. It is signaling reach, and doing so under live warfighting conditions.”

Kasapoğlu, who focuses on political-military affairs in the Middle East, said the implications for NATO are “immediate and structural.” 

“With the limited exception of the Iberian Peninsula, the alliance’s territory now falls within Iran’s evolving missile engagement envelope, including systems derived from its SLV [space-launched-vehicle] program,” he wrote. 

Iran, which has denied firing the munitions, utilized a two-stage ballistic missile that has an operational range of about 2,500 miles, according to Israeli military assessments. NATO Secretary-General Mark Rutte said during a recent interview that the alliance “cannot confirm” Israel’s claim that Iran fired the missiles. 

“But if this would be true, it is the more evidence that what the President [Trump] is doing here, taking out the ballistic missile capability, taking out the nuclear capability from Iran, is crucial,” Rutte told CBS News’s “Face The Nation.” 

United Kingdom Defense Secretary John Healey did not rule that Iran has the capacity to reach the U.K. with its missiles but argued that military leaders do not think Tehran plans to fire them. 

“We have no assessment of Iranian plans to strike London,” Healey said while on Sky News. 

Carl, of the AEI, said the challenge is not knowing if Iran unveiled a new capacity on its firing at Diego Garcia, located around 2,360 miles from Iran and a spot that can accommodate U.S. long-range bombers, or if Tehran employed a modified variant of an existing missile with only a lighter warhead that would allow it to travel farther. 

“Because of this ambiguity, it’s difficult to say, ‘Hey, is this just a tweaked version of the kind of thing that Iran has long demonstrated, or is this something else of an entirely different sort, perhaps derived from their ostensibly civilian space program,’” Carl told The Hill this week. 

Taleblu, of the FDD, said there are two options when examining which missile Iran fired at Diego Garcia, both of which would have to be modified: Khorramshahr, a liquid-fueled, medium-range ballistic missile, which was first fired in early 2017 and has a range between 2,000 and 3,000 kilometers; or solid propellant SLVs that Iran was able to retrofit with a new reentry vehicle that could “shield something of this size, and that has to go this distance.” 

“If it’s the latter, what kind of foreign support, if any at all, did the regime receive,” Taleblu asked. 

Kasapoğlu argued that, based on Israeli military assessments, Iran likely used an SLV-derived architecture, rather than the Khorramshahr.

“Systems such as the Zoljanah, the Qased, and—likeliest of all—the Ghaem-100 provide a closer design philosophy analogy than the Khorramshahr to the strike parameters observed in” the attack, he wrote in a report that was published Tuesday. “These projectiles combine verified multistage architectures with demonstrated advances in solid-propellant technology and staging sequencing and exhibit range characteristics consistent with the reported Diego Garcia strike profile.” 

During a Senate Armed Services Committee hearing, Sen. Tom Cotton (R-Ark.), who is also the chair of the Senate Intelligence Committee, asked Gen. Stephen N. Whiting, the commander of U.S. Space Command, if Iran’s SLV program is “just flimsy cover” to develop an intercontinental missile that could reach the U.S. homeland. 

“I do think they were developing intercontinental ballistic missile, senator,” Whiting told Cotton. 

Last year’s report from the Defense Intelligence Agency said that Iran has space vehicles it could use to develop an ICBM, but that it could take up to 2035 to develop 60 intercontinental ballistic missiles.

CIA Director John Ratcliffe told lawmakers during a Senate Intelligence Committee hearing that Iran is gaining experience in developing long-range missiles, with ranges of 3,000 kilometers, saying if left untouched, Tehran “would have the ability to range missiles” to the continental U.S.

“It’s one of the reasons why degrading Iran’s missile production capabilities that is taking place right now in Operation Epic Fury is so important to our national security,” Ratcliffe said during the hearing.

Defense Secretary Pete Hegseth referenced the Diego Garcia incident while discussing the U.S. war against Iran, arguing that Tehran has deceived the public again about its missile capabilities. 

“For years, they told the world that their missiles could only range two kilometers. Surprise yet again, Iran lied,” Hegseth said during a Thursday Cabinet meeting at the White House. 

Carl, of the AEI, said that while Iran has worked on bolstering its missile systems, precision is not yet its strong suit. 

“Of course, that varies from missile system to missile system, and they have a whole bunch of different variants,” he said. “But in general terms, one of the things with which Iran has really struggled is hitting precise targets, especially as far away as Israel.” 

Taleblu, of the FDD, said Iran’s expanding missile reach across the region indicates that the U.S. “must succeed” in its mission to handicap, meaningfully set back, if not destroy, Tehran’s missile systems, adding that whipping out launchers is not going to do much to alter the nation’s missile capacity or capability down the line. 

“Now, there are strikes against missile production and assembly centers, but there has to be a lot more against a known arsenal and against a place where such a projectile could have been housed or assembled or stored or launched from,” Taleblu said. “So to me, this means you actually cannot divorce the military mission from the inherent logic to move swiftly against the regime’s missile program.” 

Kasapoğlu said Iran’s reach extends “well beyond” Europe and Tehran’s missile program has always had a goal of having the continental U.S. within striking range. 

“For the Islamic Republic, a demonstrated range of 2,500 miles is not an endpoint, but a developmental midpoint,” he wrote. “For the West, Iran’s attempted strike on Diego Garcia serves as a marker that Tehran is moving deliberately toward intercontinental capabilities.”

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