International relations - what is appropriate and what isn't?

Comments on Vikas Kumar “China: Condemned to repeat the mistakes of the United States?”, 20/11/2010, http://www.eastasiaforum.org/2010/11/20/china-condemned-to-repeat-the-mistakes-of-the-united-states/
There should be a discussion on and distinction between what is reasonable international influence and what is undue interference of sovereignty of a country.

A good example but bordered on the extreme is the invasion of Iraq by the willing of coalition.

There is a view that China's foreign policy may still be based on the five principles of non-interference and etc., that some argue is outdated.

But there should be a limit in terms of both sovereignty and external intervention, otherwise things could easily get out of hands and everything and anything may be justified in terms of either sovereignty centric or intervention centric.