A problem is with Sessions analogy is that the NSA warrantless wiretap flap is not about spying on the enemy, but spying on ordinary Americans without a required court order. The spying took place not on the battlefield, but inside America. In America, our Government can't just kill people it suspects of being a terrorist -- even if the person caught in the act. Yet.

Sessions' analogy reminds me of the Queen in Alice in Wonderland: First the punishment, then the verdict.

In fairness to Senator Sessions, here is his entire comment from the CBS transcript (pdf):

SCHIEFFER: So, senator, what is the best argument you can make about why you believe the president has this authority?

Sen. SESSIONS: Well, it's necessary. We are at war. That group, al-Qaeda,
has declared war on us, that Congress has authorized the United States to
conduct war against them. As an incident to war is the power to surveil the
enemy and to inter--intercept any communications they have. We know before,
they used foreign communications into these sleeper cells that activated and
did the 9/11 attack. So I think if we can do that, it's appropriate, it's
necessary, and it's legal, both under the authorization to use force--because
when you authorize our military to use force, they can kill the enemy without
a Miranda warning, they can put them in jail without a trial. And to be able
to intercept their communications is legitimate. Remember, it's not any
foreign communication, it's only communications connected to al-Qaeda. That's
international phone call from a foreign spot into the United States that
implicates al-Qaeda, not Hezbollah or any other group. It's a narrow
approval. And finally, the Congress, congressional leaders, were informed,
and none of them objected.