This article originally appeared in Geopolitical Monitor.
By Joe Varner, March 24, 2026
On Friday, March 20, Iran launched two intermediate range ballistic missiles (IRBM) toward Diego Garcia, a US-UK base in the Indian Ocean over 3000 kilometers off its shore. One missile malfunctioned and the other was intercepted by a United States SM-3 system. However, the fact that no damage was done risks obscuring the more important reality — Iran has demonstrated an ability to threaten one of the most remote and strategically important military installations in the Western defense network.
Iran launched the two IRBMs at the British overseas territory after the United Kingdom announced that it gave the United States permission to use the Diego Garcia base for its four-week sustained air campaign and strikes on Iran. The British government had previously denied the United States use of its bases in the war with Iran and the Iranians launched their missiles in retaliation for the change in London’s policy. What appears to be a failed strike instead signals a deliberate expansion of reach and capability with implications extending well beyond the Middle East and the Indian Ocean.
Diego Garcia has long served as a secure hub for long-range strike operations and logistics across the Middle East and Indo-Pacific, with its isolation functioning as a form of strategic protection. The attempted strike calls that assumption into question by showing that distance is no longer a reliable buffer against emerging missile capabilities. The system believed to have been used, the Khorramshahr-4 IRBM, reflects a significant evolution in Iran’s missile program, combining extended range with features designed to complicate interception and enhance survivability. While previously assessed at 2,000 to 3,000 kilometers, it may now exceed 4,000 kilometers, transforming it from a regional instrument into one capable of projecting risk across a far wider geographic space. Its maneuverable re-entry vehicle, midcourse guidance, rapid launch capability, and mobility point to a system intended to operate credibly against defended targets in a contested environment.
The broader significance lies in Iran’s decision to demonstrate this capability against a target far removed from its immediate region, signaling that its strategic horizon has expanded. A system capable of reaching Diego Garcia is not designed for short-range regional contingencies against Israel but for depth, bringing parts of Europe and critical infrastructure across areas of Asia into clearer focus. If current estimates hold, much of Europe falls within potential reach, with Western Europe increasingly exposed. For Canada, this shift is not abstract.
NATO commitments bind Canadian security directly to that of Europe, and Canadian forces deployed in Latvia operate within a framework that has traditionally assumed stability beyond the front line. The expansion of long-range missile capabilities compresses that strategic depth, while Canada’s continued position outside the United States ballistic missile defense system raises increasingly difficult policy questions as threats evolve in the NORAD sphere.
The implications become more serious when delivery systems are considered alongside payload potential, as the Khorramshahr-class missiles can carry substantial warheads, and Iran’s nuclear trajectory raises the possibility of a future convergence between advanced missiles and more destructive payloads. At the same time, Iran’s reliance on proxy networks introduces the risk that elements of this capability could be distributed, creating a more diffuse and unpredictable threat environment. The successful interception will be cited as reassurance, yet missile defense operates within limits defined by scale and timing, and its effectiveness diminishes as attacks grow in complexity. What this episode demonstrates is not failure, but that existing defenses are being tested against increasingly capable systems.
Canada has long relied on geography and alliances for strategic insulation, yet advances in missile technology are steadily eroding that advantage by reducing the relevance of distance. Diego Garcia was targeted precisely because it was presumed safe, and in demonstrating that even such a location is no longer beyond reach, Iran has signaled a shift in the boundaries of the threat environment. What matters is not the outcome of this strike, but the capability it revealed and the direction it points. Canada and its NATO allies must decide whether to act while there is still time to shape that trajectory or accept a future in which these threats are entrenched and far harder to counter.
Joe Varner is a senior fellow of the Macdonald-Laurier Institute, and the Center for North American Prosperity and Security in Washington, D.C.
