Iran has a strong nuclear weapon development program. Negotiations could not halt it - they stall negotiations and continue development. So if they continue development during negotiations, why shouldn't the US continue her own parallel military route?
As for delivery, Iran does have missiles capable of launching a nuclear weapon at American assets in the Middle East, or American allies. Or even to just float it over on a ship.
Iran has a strong nuclear weapon development program. Negotiations could not halt it - they stall negotiations and continue development. So if they continue development during negotiations, why shouldn't the US continue her own parallel military route?
As for delivery, Iran does have missiles capable of launching a nuclear weapon at American assets in the Middle East, or American allies. Or even to just float it over on a ship.