Questions on NSA Data Gathering Legality

I'm still on the side of defending the NSA surveillance program (with all due respect for concerns of abuse and whether it has come to exceed authority, and a strong desire to defeat our enemies so we no longer need the program), but I should note this attack on the legality.

Of course, my tentative approval for a program I would not accept in peacetime is in part based on the notion that we are waging a war against jihadi murdering scumballs.

What's President Obama's justification when he insists the tide of war is receding?

I'm still persuadable on the issue. But it's so far outside my lane that I hate to leap to conclusions.