Violence left to God alone? Paul A.

Hello Lane,
I enjoyed your sermon, and the message that we must be patient and let God deliver justice, "though it may be late", and that only God's use of violence is justified. In the past many Christians have told me that, and every time the same question comes into my mind: What happens with continuing progressive violence? It doesn't seem morally correct for us to sit around and wait for God to do justice to end a crisis. Could it be that we are the "tools" of God to end a crisis? In particular, crisis in Darfur seems to be ongoing with hundreds of innocent people being slaughtered and raped in their home villages. If diplomatic initiative to end the crisis fails, is the use of violence (i.e. military deployment by foreign nations) to end the crisis justified? It appears that there are plenty of situations in which the use of force by humankind seems to be the only effective action to protect innocent people.
Similarly, the Myanmar is desperate for foreign aid in the aftermath of a cyclone. It has been projected that thousands more may die in the absence of proper food, water, sanitation, and medical care. To this day, Myanmar's ruling military junta is reluctant to allow outsiders in to distribute aid. If efforts to reach a timely diplomatic compromise fail, is it just for us to launch a humanitarian invasion (use of violence) to protect innocent people and prevent a possible epidemic?
Another general example is the case for various African countries. Is it just for citizens of the country to use force in an attempt to rebel against a ruling tyrant to fight oppression? I understand that unfortunately many successful rebellions against a tyrant lead to another tyrant, but the idea of using violence in an attempt to protect the freedoms of the people is there.

Is this an exception to what you said, or would you say there is always an alternative to violence? If you can help me clear up this moral dilemma or point me in the right direction, I would greatly appreciate it.

Thanks a lot,
Kind Regards,
Paul A.