War and peace in Syria

With the Syria conflict heating up, and the US trying to drum up support for an attack on Bashar al-Assad's murderous regime, voices urging caution and restraint are becoming louder. Pope Francis has called for spiritual warfare on behalf of peace:
This coming Saturday we will live together a special day of fasting and prayer for peace in Syria, the Middle East, and throughout the world. I renew the invitation to the whole Church to live this day intensely, and even now I express gratitude to the other Christian brethren, to the brethren of other religions and to the men and women of good will who desire to join in this initiative, in places and ways of their own. I especially urge the Roman faithful and pilgrims to participate in the prayer vigil here in St. Peter's Square at 19.00, in order to ask the Lord for the great gift of peace. May a powerful cry for peace go up from every land!

If you're wondering, 19:00 Rome time is 1:00 pm Eastern Time in the US. Good time for a rosary.
But, I wonder whether peace in the case of a civil war that has killed 100,000 Syrians is a matter of prayer, not that it would hurt to try. The Syrians have been pounding away at each other with explosives and bullets for months now. The recent chemical attack, whether perpetrated by Assad or the rebels, has upped the ante and crossed the West's "red line," triggering serious talk of an attack.
Does the Pope equate war with US intervention? Given the timing of his plea for peace, you could read it that way. No doubt, war has been going in in Syria for months without a papal call for peace. It would be disappointing if President Obama got the "warmonger" tag for threatening to take out Syria's capacity for launching chemical warfare on its citizens. All while Assad escaped condemnation altogether.
But is peace, which all Christians should pray for and work toward, the absence of violence? Is limited "war" (if knocking out some radar batteries counts as war) permissible to end appalling and unending violence? No doubt, diplomacy has been tried, and the killing goes on. Calls have made been for Assad to stop his death spree, and the killing continues. Threats have been made and the machinery of war put into motion, and the killing continues.
Moral force can be effective against an enemy that sees itself as moral. But against an enemy that has no conscience, or that claims to be acting in accord with conscience, there are but two options: to remain silent while the killing continues, or to take action.
I am disappointed that America's appears to be among a very few voices raised in protest against Assad's death-dealing rampage. Peace in this case, it's sad to say, will not come from the recitation of prayers and fervent pleas for an end to violence. It will come from the unified voices of the world's armed powers, working together to offer a credible threat to the Syrian government, and if necessary, to follow though on that threat.