What limits should - or should not - be placed on the president's ability to direct drone attacks against our enemies?

As I'm writing this, there's a debate going on in the Senate over the ability of the president - any president, not just President Obama - to use drones and any other method he chooses to strike at people he might believe are enemy combatants (see this link for the story). The question is what standards ought to be in place to ensure that this power is not used arbitrarily. Questions have been raised about whether these strikes can be used against American citizens (they have been already - in Yemen) and on American soil.

In a broader sense though, this question is about what a president's responsibilities are to protect the US from the variety of attacks that are now possible - both terror and cyber in addition to old fashioned methods - and what responsibilities other institutions have to ensure that presidential power in this arena is contained.

I want you to read up on this - I've posted a few items on this on the blog - and develop a topic on the subject. I'll help.