Most of the discussions on liberty by John Stuart Mill center upon individual freedoms within a society such as you find in England at the time of his writing. The principle of negative liberty is often laid at his feet. I am not familiar with Mill’s position on international affairs. Burke would be worth studying on this issue since he was involved with the issues of colonization and war. He was opposed to the intervention of England in America, but he was not opposed to colonization or British force. I do not know enough about Burke to speak intelligently upon how he combined liberalism and colonization. Locke was the primary philosophical force behind Jefferson and others of that time. Locke was more about the social contract than anything else. I do not know what Locke’s views were on international relationships. My view is that Washington’s views on political affairs was based more upon commonsense and experience than upon a political philosophy. It seems to me that the issue with which we are debating is the relationship between Liberalism and international or global nexus. This is my question. Is the use of military force in international affairs contrary to Liberalism?
The Social Contract tells us that individuals have their natural rights and loan it to government. But government cannot have powers loaned to them that the people themselves do not have. (We can have police enforce laws against armed robbery, because I as an individual can protect my property and self against armed robbery so I can “loan” that power to my government... On the contrary, I cannot steal money from my neighbor to help a person in need as that is theft; therefore, I cannot “loan” that power to the government either... i.e. redistribution of wealth is still theft).
If we take that view of legitimate government powers must originate from the individuals that loan those powers to the government, then how can I justify a non-defensive use of force against another country? If I, as an individual, cannot attack my neighbor then I cannot authorize my country to attack another country. However, if my neighbor attacks me I can defend myself and if a nation attacks the United States we can defend ourselves.
Most libertarians do not oppose national defense. Ron Paul voted FOR the operations in Afghanistan for example. However, that doesn’t justify “nation building” in Afghanistan or pre-emptive war in Iraq through the lens of the Social Contract.