Is John Locke's philosophy relevant to nations in today's world?

Locke asserted that the social contract was entered into by the people and the sovereign in order to reinforce the natural (God-given) rights of man. When the people no longer found the contract applied in their best interest, they had the natural right to break the contract. Thomas Jefferson et al used Locke’s idea of the limits of the social contract as the basis of the American Declaration of Independence, following the urging of Thomas Paine and others to apply Locke’s views to the situation experienced by the thirteen colonies at the hands of England. Is Locke’s position relevant to contemporary nations? Consider Libya, Egypt, Tunisia and post-colonial Africa or the Middle East in general.