Bush is saying that no man is an island. Essentially, if we are going to promote liberty for all, we cannot pretend as if the oppression of our neighbors does not affect us, and therefore ignore it.
I see it differently.
That phrase can only imply we are headed toward more globalism, less individualism, more wealth transfer, less independence, more tax slavery, less personal responsibility, more U.N. kissassing, less America first.
That is a very, very disturbing sentence in his speech.