This article promotes the "National Interest"

       Lately our illustrious President has proclaimed that we need to impose stiff tariffs and prosecute immigrant families because of "national security". 

      How creative of him.
      Throughout history, politicians and rulers and governments have inflicted all manner of authoritarian, imperialistic, omnipotent power and control over their people.  They command the people to follow, to obey, to hand over their money and control over their lives and property and their private affairs, else face serious punishment, even to the death if they do not comply. 
      How do they accomplish this without the people refusing or revolting?  Easy.  All they have to do is declare that this heavy-handed governmental overreach is to promote the National Interest, or National Security, or the Common Interest, or the Common Good, or the Common Welfare, or the General Welfare.  Pick your poison.
      In general, liberals prefer the adjectives "common" or "general", while conservative prefer the adjective "national".
      Even our illustrious Constitution declares, in its opening statement, that one purpose of the government is to promote the "General Welfare".  I suppose that would be a pro-liberal declaration.
      Another good example is the law that says TSA agents must grope our genitals before we can board an airplane, because it promotes "national security". 

"abstract"

      What exactly do these words mean?  To decode the meaning, one must first understand that the terms "nation" and "common" and "public" and so forth are ABSTRACT CONCEPTS.  There is no tangible object out there called a "nation" that one can touch, such as, say, a "chair" or a "tree".   They only exist in the imagination, and on paper. (Yes a "nation" generally has a defined area of LAND that one can certainly touch, but we're discussing political science here, not real estate.)
      Abstract concepts do not have feelings.  Even if we grant that a "nation" is a physical, inanimate object, the fact remains that inanimate objects do not have feelings either.  So how in the world can something with no mind and no embodiment have "interest" or "good"?

      The answer, of course, is that the words really don't have any meaning. They're just words.  They sound grandiose, but that's about it.  Thus, one can define them however one chooses.   So if someone claims that the government must do such-and-such because it promotes the "Common Welfare", then anyone who disagrees clearly doesn't give a damn about the Common Welfare.  Case closed, debate won, argument settled.
      Furthermore, I must point out that I, too, am a "common" part of this "nation".  And it's certainly not in my "interest" to cough up more taxes for the latest social engineering project, be it domestically here or in some far-off foreign corner of the world.  Or to have my genitals groped by a government agent.

Joffrey Baratheon

      Another term politicians use to gain more power is "treason".  Whenever I hear the word, I think of Joffrey Baratheon in Game of Thrones, who charged anyone with "treason" who dared to disagree with him or challenge his claim to the throne.  They were always guilty, of course, and quickly had their heads removed.  Moving out of fiction and into the realm of genuine history, Henry the VIII of England was notorious for chopping off heads of countless innocents because, as he said, they committed "treason".

      My advice to all is to grow some cynicism.  Don’t follow all the other sheep just because another blowhard politician says the government needs more power and control for "national security" or whatever.  If you really care about the "common national interest", then seek out ways to make government smaller, not bigger.