There is no officially declared “war with Iran” in the sense of a formal, named, world-recognized war that began on a single agreed date, but there are several different conflicts people might mean when they ask this. To answer your question properly, we need to pin down which “war with Iran” you’re referring to.

The different “wars with Iran”

When people say “war with Iran,” they usually mean one of these:

  1. The Iran–Iraq War (1980–1988) – a full-scale conventional war between Iran and Iraq.
    • Open warfare began on 22 September 1980 , when Iraqi forces invaded western Iran across the border.
 * Iraq later claimed it really started on **4 September 1980** , when Iran shelled border posts, but the widely accepted start of the war is 22 September.
  1. The 2025 Twelve‑Day War between Iran and Israel – a short, intense conflict.
    • This conflict began on 13 June 2025 , when Israel carried out surprise airstrikes on Iranian military and nuclear facilities.
 * It lasted from **13 to 24 June 2025** before a ceasefire.
  1. The broader, long, mostly undeclared U.S.–Iran conflict – “cold” and “shadow” war.
    • Some analysts trace this back to 1979 , with the Iranian Revolution and the U.S. embassy hostage crisis.
 * Others point to the **1980–1988 Iran–Iraq War** , where the U.S. supported Iraq, as the point where a sustained, violent confrontation really took shape.
  1. The recent “war on Iran” or “Iran war” in media and YouTube explainers
    • Recent pieces describe an “Iran War” as part of the current cycle of strikes and counter‑strikes between Iran, Israel, and the U.S., but even they note the roots go back decades, especially to 1979 and onward.

So, “when did the war with Iran start?”

Because there is no single, universally recognized “War with Iran” like “World War II,” the start date depends on what you have in mind:

  • If you meant the big classic war involving Iran in the 20th century :
    • That’s the Iran–Iraq War , and it started on 22 September 1980 with Iraq’s invasion of Iran.
  • If you meant the recent shooting war between Iran and Israel that was all over the news:
    • That’s generally referred to as the Twelve‑Day War , starting 13 June 2025.
  • If you meant “when did the U.S. and Iran basically start being in a state of war?” in the broader sense of ongoing attacks and proxy fighting:
    • Many journalists and historians point to 1979 and the hostage crisis as the psychological and political start of this long conflict.

Quick Scoop (forum-style summary)

Q: “When did the war with Iran start?”
A: There is no single, official “War with Iran.”

  • The big conventional war is the Iran–Iraq War , starting 22 September 1980.
  • The short, recent Iran–Israel clash (“Twelve‑Day War”) started 13 June 2025.
  • The broader U.S.–Iran conflict is often dated back to 1979 and the revolution/hostage crisis.

If you tell me which conflict you meant (Iran–Iraq, Iran–Israel, U.S.–Iran, or “the current Iran war” you’ve seen in headlines), I can narrow it to one clear timeline and walk through the key milestones.