Tactical or strategic nuclear weapons count. Clock starts ticking on a month when the US drops the bomb.

Market resolves NA if the US hasn't used a nuclear weapon in Iran by September 1st or if the US hit the Fordow enrichment facility with conventional weapons and still hasn't used a nuclear one two days after (timing might be fuzzy depending on my news checking). Tight NA resolution timeline to not keep mana locked up on a market that resolves NA.