I consider myself a conservative-libertarian (small 'c' and 'l'), but I am always amazed how some, not all, Libertarians are both intellectually shallow and arrogant. When pushed they start spouting "natural rights" (or some even have the presumption to call upon the "Golden Rule"), but what the hell is that?
Jefferson said "natural right" was the right to "life, liberty and the pursuit of happiness". Genghis Khan said "man's greatest good fortune is to ride into battle and defeat your enemy, take his ponies and his possessions, rape his women, burn his cities to ashes, and ride off to the sounds of his women weeping and wailing in despair". Which one is it?
Without the context of a social compact which creates a society inclusive of individuals but apart from them, which Libertarians seem to reject as anti-individualist, Genghis Khan's ideas seem to historically win out. Only with a social compact that accepts and protects individual liberties do we see Jeffersonian concepts of "natural rights" prevail. In the absence of such a social compact we have usually lived in either a "state of nature" that is "solitary, poor, nasty, brutish, and short", or in a state of outright tyranny. Without the individual protections contained within a social compact there can simply be no individual liberty as we have been taught to understand it.
In regards to foreign policy there simply is no social compact, and as such we should not expect Libertarian ideals of "natural rights" to prevail. How can this be so difficult for Libertarians to see?