You mean like the way the US government, believing itself too rich and powerful to have to worry about being brought to trial for international war crimes, flagrantly flouts international law?
[WS:] Exactly! Few things offend me more than pious pricks wrapping their greed and self-interest in ethical, religious or patriotic claims. I'd rather deal with straightforward thugs like Hermann Goering who are at honest about who they are.
As to the rest of your posting, I think you misunderstood my argument, but perhaps I was not very clear either. So let me reiterate.
Ethics can be grounded in two different normative principles: utility or duty. The utility principle fundamentally holds that good or ethical conduct is one that benefits the actor. The duty principle, in turn, holds that ethical conduct is one that is consistent with something that has ethical value in itself.
The utilitarian ethic is individulalistic and relativistic by its nature, since it starts with the individual - as almost everything else in British philosophy - but it can be extended to the collective (e.g. Pareto optimum which attempts balances benefits of all individuals in a collectivity). I think its main appeal is that it is relatively easy to grasp by laymen and has a veneer of practicality, as you pointed it. The argument has also been criticized on many grounds (c.f. http://en.wikipedia.org/wiki/Utilitarianism). My problem with it is not that much that it may lead to behavior that most people would consider unethical (any principle can) - but that it rests on philosophical assumptions about the nature of human cognition and society that I find objectionable.
The first assumption is the focus on the individual and treating the collective society as a mere sum total of individuals, which is particularly evident in the concept of Pareto optimum. The second assumption is cognitive omniscience of human actors, that is, knowledge by individual actor which behavior brings what utility or disutility to himself and other within various time frame. Without those two assumptions, the utilitarian ethics is nothing more than saying "do what suits you at the moment and hope that things will sort themselves out in the long run." If this is to be a guiding principle rather than ex post facto rationalization, the actor must have prior knowledge of all possible consequences of his behavior not just for himself in a long run, but for others as well, and that borders on impossibility.
Deontological ethics, otoh, starts with the concept of duty or obligation to do what is considered right, and thus avoids the problem of having omniscient knowledge to be able to act ethically. Almost every person can be taught a set of principles to follow.
I further argued that while these specific principles are culturally constructed and depend on tome and social context, the concept of duty is innate - most people are born with it, just like they are born with the ability to learn a language (but not necessarily English or any specific language). This is yet another advantage of the deontological approach - it explain why people with little formal knowledge and schooling can and do act ethically. In the utilitarian approach, by contrast, you need to be an applied mathematician to figure out what the optimal and thus ethical behavior is.
I hope this clarifies the issue a bit.
Wojtek