It has to be done in advance, but yes one of the reasons is to confirm arms reductions: https://www.armscontrol.org/factsheets/openskies https://www.armscontrol

It has to be done in advance, but yes one of the reasons is to confirm arms reductions: https://www.armscontrol.org/factsheets/openskies https://www.armscontrol.org/factsheets/openskies I don't think that US & Russia has any arms reductions treaties still in force, but the Open Skies Treaty is still there.