proper balance in a democratic society concerning the need to preserve civil liberties as well as ensure national security in a time of threat or war?...

What should be the proper balance in a democratic society concerning the need to preserve civil liberties as well as ensure national security in a time of threat or war? How can too much emphasis on the one diminish the importance of the other?
From your perspective, how well has American government and society balanced these two dimensions during the past several years in its efforts at counter-terrorism? In what ways has the nation been successful? And not-so-successful? Be sure to cite specific examples.
Over the past few years, there has been considerable media attention, commentary and analysis given to series of previously-undisclosed electronic surveillance actions taken by the Obama and Bush administrations as part of their counter-terrorism efforts (We'll see what happens during the Trump years...). For some Americans these actions are controversial and impinge upon citizens' civil liberties. For others these actions are necessary in order to endeavor to keep the nation secure. How do you come down on this issue? What other examples can you cite to back up your arguments (there should be plenty to draw upon from the last dozen years or so...do a bit of poking around!)?