Sovereignity of nations and the legitimacy of military action

This is a debate proposed at this website:
http://www.livejournal.com/community/philosophy

Here is the question:

Sovereignity of nations
This old philosophical paradigm about the sovereignity of nations and of the nation's sovereign, where does it stand these days? I am wondering about this in particular after it has turned out that Iraq never had any WMDs, and that the US populace was misled. The only current 'rationale' is that Iraq's old sovereign, Saddam Hussein, was ousted from power.

My reply:

I understand the concept of sovereignty as one of popular consent. No coutries can violate another country's sovereignty unless there has some evidence that there is a popular consent (from local nationals) for forcing a despot/dictator out of power.

In the case of Iraq, I don't remember hearing any evidence that there was a call from Iraqis for a foreign invasion to force Saddam Hussein out of power. I don't believe either that the local population of any country are likely to call for a military invasion for one good reason. They have brothers... cousins... sons... serving in the armed forces.
I only see the case of genocide where military action can be justified EVEN IF there is no clear demand for help from the local population. Exemple: Cambodia's invasion by Vietnam in 1979.

Sailom