There is no option "but they should!" - why?
Please read the poll carefully - you're meant to identify deal-breakers that would make you oppose the intervention. If none of the options are applicable to you, then you are supportive of intervention, even if we end up killing way more people, even if our invasion is based on lies, even if we lose countless American lives and resources, and so on... I sincerely doubt this is true for anyone.
But if you are looking for a joke option, there is the "none of the above" at the bottom.