I don’t think deploying “80% right” tools for mass surveillance (or anything that can remotely impact human life) counts as lawful in any context.
Just because the US currently lacks a functioning legislative branch doesn’t magically make it OK when gaps in the law are reworded into “national security”
The tools are not good enough to be ethically deployed, least of all for surveillance.
Just because Congress is failing to do its job doesn’t mean the executive branch should simply do what it wants under the guise of “national security.”
Some people feel that mass surveillance is wrong whether it is domestic or not. For those people, being ok with mass surveillance as long that it is not done to your kind is a morally wrong stance.
No other country should dictate what our military is or is not allowed to do. As they say all is fair in love and war, and if we want to break some international treaty that is our choice to do so. Both are based of domestic decisions of what should be allowed.