The US, like every nation, needs both public and protected information.

Before I became an ambassador, I worked for many years as a lawyer advocating for freedom of expression and for public access to information in the United States. Today, confronted by WikiLeaks, both roles lead me to the same conclusion - the disclosure of purported classified government information, including as advocated by WikiLeaks, is bad for free expression.

Even as a civil rights lawyer, I understood that protecting the confidentiality of sensitive government communications was vital to maintaining a free society, and confidentiality is entirely consistent with America's and Australia's bedrock commitment to freedom of expression.

And today, as a US diplomat, I've been impressed that this commitment is shared throughout our diplomatic corps, which work around the world to promote both free expression and effective government.

As a lawyer, I handled many ''free expression'' cases over two decades. These included representing media organisations demanding that the government unseal records or remove gag orders. I remain passionately committed to freedom of expression, and - like WikiLeaks - I have quoted president John F. Kennedy's observation that as a free nation, ''we decided long ago that the dangers of excessive and unwarranted concealment of pertinent facts far outweighed the dangers which are cited to justify it''.