When not enforced, such obligations are meaningless.

So does everyone.

But guess what cops are human too ergo they will on occasion make mistakes, lie, steal, cheat etc.

And when they lie, steal, and cheat, they should be punished. In fact, they should be punished much more harshly than the general public, because it is their duty to prevent lying, stealing, and cheating. They should be held to a higher standard.

This cannot be stressed enough. Anyone who enforces a rule through violence but is not subject to that rule is nothing more than a thug.

This made me laugh. Applying this rule to the US is hilarious. The collection of Gitmo detainees, drone victims, the tortured, the extraordinary rendered, bombed, shot and otherwise victimised non-US citizens that happened to be in the wrong place at the wrong time when Uncle Sam came knocking over their countries probably aren't smiling with me.

You're really surprised that citizens of a country expect to be treated better by their own government (which, in essence, is the expression of their own will) than non-citizens are? For examples of this, see literally every society that's ever existed in the history of mankind.

That's not to say that any of the things you mentioned are ethical or that I agree with them at all, but it's not too difficult to see the difference between being victimized by an external force (which is essentially just garden-variety "humans are shitty"-ness) and being victimized by an entity that is supposed to represent you.

The main difference with the US is that the public image and repeated, vehement rhetoric is freedom and peace and equality for all humankind. Yet dig a little deeper and the double standard about citizens and non citizens and how they are treated becomes very apparent, far more so than in (say) some of the european countries.