From your reference to torture in the OP...
Granted, I'm new to the arena of foreign relations - or rather, the buisness of defining terms associated with it - but the general spread of basic human rights and peoples' condemnation for torture (once a public spectacle), to a liberal, shows public progress.
I suppose it does, but that's kind of facile and that's why I raised my disagreement at what this professor is apparently teaching you about the academic discipline of 'international relations'. It seems like your class is only 'glossing over' this topic, rather than this being a full course in 'international relations'.
Please forgive me, but I have taken many such courses in my undergraduate studies and also this topic impinges upon my graduate studies in philosophy (ethics), so I'm just probing a bit to see what your knowledge and interest level in this topic is. My replies can be seem cryptic, obfusicating, pedantic or condescending if I don't 'tune' my replies appropriately. I never know if others are high school, college, university or graduate-level students.

As for universal human rights, I'd say that even basic human rights haven't actually spread at all outside the 'Western Pale' as far as I can see. Indeed, all the progress in 'human rights' is political progress in trying to build majority support for the idea inside the 'Western Pale'.
To put it simply, Africa and South America have no more and no less human rights now than they have ever had, or had 50 or 100 years ago. I'd be quite pleased to be proven wrong here, if anyone has any substantial evidence to the contrary. I'm not talking about fanciful rhetoric in lofty statutes, laws or proclaimations here - I'm talking about actual results on the ground for poor people. Poor people (outside the west) just don't have any actual human rights in actual reality.
As for torture, are you familiar with Michel Foucault's brilliant sociological study on the evolution of the character of state punishment since the 1500's?
Discipline and Punishment is the title - a very short book - along with
Madness and Civilization a related study of how society treats mental illness - I recommend most highly. Probably the single most impressive piece of academic analysis I've ever encountered (definitely accessible to a 'non-specialist' reading audience).
My point here is that 'torture as civic spectacle' disappeared a good century or two before the dawning of the 'enlightenment' and the birth of the ideals that have since spawned the ideals of 'universal human rights'.
It's a major tenet of their philosophy, I thought, because it proves that progress is possible and the motivations of states do not wholly dictate global politics... but indidualism does.
Well yes, the idea that the human condition can theoretically be 'improved' is a fundamental tenet of classical liberalism and is the foundational distinction of 'tory vs whig' - the earlier terms for what is now deemed to be 'conservative vs liberal'.
As for the assertion that the actions of individuals can have international effects, that is an unproven assertion that is popular on both the left and the right. I've see little evidence of it in a modern context.
It was part of my argument to show that UHR means something to liberals, not neccessarily cause they are concerned with UHR specifically, but rather the world's new \concern for UHR proves that statism is NOT the only determenent factor in world politics... but so is individualism.
That's a reasonable argument to make.
Personally, I'd reject the argument because true classical liberalism is traditionally as suspicious of the state as they are of large corporations or religious institutions. Classical liberalism seems to ally with the statist principle only on the basis of a 'lesser of two evils' principle (holding that statism is less bad than anarchism).
Statism is a passion only of authoritarians. No liberty-loving liberal can love the state.
And this brings us to the infamous American cultural 'redefinition' that liberalism=socialism. Of course, socialists always love the state. Real liberals don't. But if one 're-defines' liberalism as socialism (as is extremely common in the USA) then it does make sense to say that liberals love the state.