A Subjective discussion about principle Human Rights

Without a doubt the most significant right a person has is the right to life. This phrase ‘right to life’ is commonly used in abortion arguments, however, I use it in its most literal sense. The most compelling dilemma a person or group will ever have to face is the killing vs. letting die distinction. This principle has been discussed from human rights philosophers like John Locke—a social contract theorist, whom (deriving and departing from the Hobbesian view of nature) argued that legitimacy in government is gained through protected natural rights (life, liberty, etc.)—to Immanuel Kant and his discussion of human freedom in Critique of Pure Reason. With a seemingly failed attempt at war in the Middle East, exponential warfare technology, and cases of genocide, the discussion of this most basic—yet fundamental—human right is ever more important.
To show the killing vs. letting die distinction and its severe compelling ability I use the following model.
Situation 1: You are between two ponds. In pond ‘X’ there are 5 people drowning. You do not know any of these people. In pond ‘Y’ there are 10 people drowning. You do not know any of these people. Neither pond can swim. You can only save one group of people. Which do you choose? (Hold your answer for now).
Situation 2: You are riding on a train. At the end of the track there is a pond with 10 people drowning. In the middle of the train track there is a person holding the tracks together above a small canyon. You can both stop the train and save that one person holding together the tracks while the 10 people drown or you can kill him and save the 10 people drowning. Which do you choose?
It seems as if situation 1 most people would choose to save the 10 people over the 5. If only because it is more people saved and less life lost. Situation 1 seems easier to answer because in that instance the actor (you) are not killing the 5 people, but you are letting them die. Situation 2, however, is much more difficult because in order to save the 10 lives the actor must kill someone. Obviously, there is a person would experience a dilemma because his or her direct actions would kill someone.
This raises the question of when is it morally acceptable to kill or let die? What if by killing 10 people we could save 100’s or even 1,000’s? Remember the Burundi Civil War between the Hutu and Tutsi, there was no humanitarian intervention there, governments were merely just ‘letting people die’ they weren’t killing them. Some political critics believed that since the Clinton administration had lost 7-10 Green Berets—highly elite Army units—in Sudan that any more losses due to humanitarian intervention would case a domestic backlash. Remember the Kosovo conflict between the Albanians and Serbs; part of NATO’s justification for intervention was on humanitarian grounds that by killing they could ‘save more lives than were lost’. Granted, it has been debated that NATO’s intervention was so that NATO could expand their powers and possibly increase its member base, but they told the world that they were intervening on a humanitarian base, to save lives by killing.
The killing vs. letting die distinction is integrated within domestic and foreign policy. It is apparent in decisions in war and office. Perhaps, we can understand the loss of life better if we use this rational model to unveil people’s decisions to kill or let die? I’d like to know what you all think.