This market will only resolve no once:
the media consensus is that the Iran war is over (not just a ceasefire), OR
a temporary ceasefire has gone on for 365 contiguous days.
Otherwise, it will resolve yes when the next Democratic party nominee for President is inaugurated and there is not an active ceasefire. If a ceasefire is ongoing at the time of inauguration, this market will not resolve until either the ceasefire ends or it reaches 365 contiguous days (inclusive of days prior to inauguration).
@FastFourier My intention was that an active ceasefire would not count as still being at war, but the market won't resolve until the ceasefire has held for a year, so it would resolve no in that case. Updating the description now to make that more clear.