Truthbringer: Just because the social contract has some unique features does not mean it is not a contract. In fact, the contract for the United States is explicitly written up in the form of the Constitution.
Also, specific examples of governments that abused their powers do not prove that governments are inherently bad(no more so than corporations who abuse the environment and their workers prove that all corporations are bad). And I would suggest that religious/ethnic wars have killed more people than governments.
As far as your argument about leaving... You are both free to leave, and free to attempt to modify the existing social contract by voting. If you had a lease for an apartment, and you discovered that some of your landlord's policies were repugnant to you, would you demand that your landlord leave?
I agree with you, Truth-Bringer, that the free market was a good idea. It is a powerful tool for making everyone's life better. However, there are many things it does NOT do well. Among other things, it deals poorly with environmental issues, health care(see cable tv infomercials), social safety nets, education, etc. We can argue about the desirability of those things, but it does not change the fact that the free market deals poorly with them.
And this brings me to a question for you. If a government should have a minimal role like defense, how is the government paying for it? Would it be a voluntary contribution system? Some kind of use-fee arrangement? I would like to be clear on your view, because when I first read it it seemed.... contradictory.
Defining contract:
http://wordnet.princeton.edu/perl/webwn?s=contract
Free market environmentalism:
http://www.econlib.org/library/Enc/E...reeMarket.html
A note: This url is pro environmental free market practices, yet admits current practical difficulties with it. And this would require fairly massive, invasive government intervention to implement.
Education:
http://www.nytimes.com/2006/07/15/ed...rssnyt&emc=rss
Health Care:
http://dll.umaine.edu/ble/U.S.%20HCw...are%20world%22
Social Safety Nets:
http://web.worldbank.org/WBSITE/EXTE...282761,00.html