Overview

The path from diplomatic tension to military strikes against Iran unfolded over nine months, from June 2025 through February 2026. This timeline reconstructs the key events in chronological order, documenting how a series of IAEA findings, failed negotiations, military repositioning, and political decisions narrowed the available options until strikes became the outcome both governments appeared to accept as inevitable.

Each entry in the timeline is anchored to a specific date and source. Where exact dates are disputed or classified, the entry notes the uncertainty. The goal is to provide a single reference document that shows not just what happened, but the sequence of cause and effect -- which diplomatic failure preceded which military buildup, and which intelligence assessment triggered which political decision.

Understanding the timeline matters because the strikes on February 28 did not emerge from a single provocation. They were the culmination of a cascading series of failures -- in diplomacy, in verification, and in deterrence -- that accumulated over months while public attention was often focused elsewhere.

What We Know

As of February 28, 2026, coverage on iran strike timeline should prioritize primary documentation and high-credibility reporting. This section focuses on confirmed information and labels uncertainty directly.

Analysis

Three turning points where diplomacy failed

The timeline reveals three critical junctures where the trajectory could have changed. First, in August 2025, when Iran expelled IAEA inspectors rather than allowing verification of the 84% enrichment finding. Had Iran permitted continued access, the US would have faced stronger international pressure to pursue diplomatic solutions before military action. Second, in October 2025, when the Oman backchannel collapsed over US insistence on "anytime, anywhere" inspections versus Iran's demand for sanctions relief before any verification. Third, in early February 2026, when a final 48-hour diplomatic window reportedly offered through Turkey was rejected by Tehran, which calculated that the US was bluffing about strikes.

The military buildup as a signal that went unheeded

Beginning in December 2025, the US force posture in the region shifted from deterrence to preparation. The deployment of a second carrier strike group, the forward positioning of B-2 bombers, and the pre-positioning of precision munitions at regional bases followed a pattern that military analysts recognized from previous operations. Israel's simultaneous large-scale exercises -- involving aerial refueling rehearsals over the Mediterranean -- were reported by aviation trackers weeks before the strikes. The buildup was visible in open-source intelligence, yet Iranian official statements continued to dismiss the possibility of a direct attack, suggesting either a genuine intelligence failure or a political decision to not appear to capitulate to threats.

The IAEA's role as the tripwire

The February 14 IAEA confirmation of 90% enrichment functioned as the operational trigger. Both the US and Israel had publicly committed to treating weapons-grade enrichment as a red line, and the IAEA finding provided the international legitimacy needed to act. However, the IAEA itself noted that its verification was based on limited sampling from before inspector access was revoked -- meaning the 90% finding carried inherent uncertainty. The gap between what the IAEA could confirm and what US intelligence assessed created a politically useful ambiguity: enough certainty to justify action, but not enough to foreclose future diplomatic framing.

What's Next

The timeline does not end with the February 28 strikes. The following developments will extend or reshape the chronology in the coming days and weeks.

Why It Matters

Timelines are how accountability works. When officials claim they "exhausted diplomacy" or critics argue strikes were "premature," the chronological record is the only way to evaluate those claims against what actually happened and when. This timeline shows that multiple diplomatic channels were attempted and failed, but it also shows that the failure points involved choices by both sides -- not an inevitable march to war.

The nine-month arc from June 2025 to February 2026 also reveals how slowly crises develop and how quickly they resolve into military action. For eight months, the dominant narrative was tension and uncertainty. In the final two weeks, events accelerated from the IAEA's 90% enrichment confirmation to active strikes in just fourteen days. Recognizing that pattern matters because future crises -- whether involving North Korea, the South China Sea, or other nuclear threshold states -- may follow similar dynamics.

For historians and policy analysts, the documented sequence of IAEA reports, diplomatic failures, force buildups, and political decisions will become the evidentiary foundation for evaluating whether the strikes were justified, whether alternatives existed, and what lessons apply to preventing similar escalation in the future.

Sources

  1. AP live updates (Feb 28, 2026). apnews.com/article/8de8054f3abd4688f894c657467ee3dd
  2. AP: US and Israel launch attack. apnews.com/article/c2f11247d8a66e36929266f2c557a54c
  3. AP: Read President statement. apnews.com/article/f662a4f3378535d81197be699fb35a3e
  4. AP: IAEA unable to verify enrichment halt. apnews.com/article/ccf574a324504b985f4b158f9d3d6941
  5. IAEA: Iran focus page. www.iaea.org/newscenter/focus/iran

Last updated: February 28, 2026. This article is revised when new evidence materially changes what can be stated with confidence.