Why did the US attack Iran? Why now?

So why is the United States once again confronting Iran? The answer starts with a long and troubled history, but it ends with a very modern concern: nuclear weapons.

The U.S. and Iran have been adversaries for more than forty years, going back to the late 1970s, when Iran’s Islamic Revolution overthrew the U.S.-backed Shah. Followed by Iranian militants taking over the U.S. embassy in Tehran and holding American diplomats hostage. Since then, Iran’s leaders have openly promoted anti‑American sentiment, often captured in the now‑famous chant, “Death to America.”

Over the decades, Iran has supported militant groups across the Middle East, most notably Hezbollah and Hamas, largely aimed at Israel, historically the United States most consistent ally in the region. Iran also clashed with the United States through proxy conflicts. In Iraq, Shia militias backed by Iran were responsible for attacks that killed many U.S. service members (Iran-Supported Groups in the Middle East and U.S. Policy | Congress.gov | Library of Congress). During the war in Afghanistan, Iranian money, weapons, and training helped fuel Taliban (https://ctc.westpoint.edu/irans-ambiguous-role-in-afghanistan/) especially with deadly improvised explosive device attacks.

Given all of that history, why is the situation escalating now? The short answer is Iran’s nuclear program. While Iran does not currently have a nuclear weapon, it does have is enriched uranium—the key ingredient needed to make one. So what’s this enriched uranium stuff all about? Well, naturally occurring uranium can’t be used in a bomb. It has to go through a process called enrichment where a gaseous form of uranium (known as uranium hexafluoride) is spun in fast rotating cylinders called centrifuges to increase the concentration of a specific isotope, uranium‑235. For civilian energy use, uranium is enriched to low levels (20 percent uranium-235).  For a nuclear weapon, it must be enriched to about 90 percent.

Last year, the US and Israel carried out air and missile strikes against Iran to destroy these large centrifuge facilities needed to convert raw uranium. However, Iran had already stockpiled uranium enriched to around 20% – 60% and not all of these stockpiles were not destroyed (https://www.scientificamerican.com/article/iran-was-nowhere-close-to-a-nuclear-bomb-experts-say/#:~:text=Although%20President%20Trump%20has%20claimed,235)%20found%20in%20the%20material.). To convert these stockpiles to nuclear weapon grade uranium, Iran claims to have smaller enrichment sites buried deep underground, some hidden in mountainous areas, which are extremely difficult to destroy.

The issue came to a head in February during negotiations between U.S. representatives and Iran. According to U.S. negotiators, Iran reportedly acknowledged that it was only a week away from being able to enrich uranium to weapons‑grade levels (https://www.politifact.com/article/2026/feb/26/Iran-nuclear-bomb-week-Witkoff-Trump/).

These events are the “Imminent Threat” that the US claimed Iran poses (https://www.pbs.org/newshour/world/read-trumps-full-statement-on-iran-attack). A nuclear threat doesn’t look like traditional warfare. There are no troops massing at borders or weapons visibly pointed at cities. Once a country has weapons‑grade nuclear material, it can hide it, move it, or repurpose it with relative ease. That material could be built into missiles, used in crude nuclear or radiological devices, or potentially passed to proxy groups or terrorist organizations.

At that point, the concern was no longer theoretical. The United States would be facing a government with a long history of hostility toward America, deep ties to militant groups, and the ability to produce nuclear‑grade material on short notice.

That combination—intent, capability, and timing—is why Iran’s nuclear program became an urgent issue again. It’s not just about what Iran did in the past. It’s about what it may soon be able to do, and how difficult it would be to stop once that line is crossed.

Leave a comment