Tuesday as a fast day for peace: Rabbi Arthur Waskow writes in The American Muslim:
What is 17 Tammuz about? It commemorates the day when the Babylonian Army broke through the walls of Jerusalem in 586 BCE, three weeks before the Babylonians destroyed the Temple.
So it is, among other things, a day of sorrow for the dead and self-restraint from killing.
My thought: — It would be both a serious expression of commitment to peace and decency and also a serious memorial to Reb Zalman Schachter-Shalomi, who died last week, for us here as well in the USA to join with Muslims on 17 Tammuz in a Hunger Strike Against Violence, and to end the day together with Iftar, the evening break-fast.
Various commentary, including Steve Norman’s short essay on why he doesn’t pray for peace.
I’m not always convinced it’s worth the time. After all, God’s track record for responding to the prayers others have prayed for a particularly broken corner of the world appears less than stellar.
There’s that … maybe. I grow less convinced the powers-that-be in the Middle East want peace. They’re all addicted to vengeance, but there’s no way an oppressed citizenry (I mean the Israelis among others) will rise up and rid themselves of their duly-elected government. Where is Palestine’s Gandhi?
I also like Sheila Musaji’s compilation here.
Mr Norman suggests a middle section of Psalm 10, but I wouldn’t be so hasty about forgetting the opening salvo in that piece. Here are verses 1-4, NRSV:
1 Why, O Lord, do you stand far off?
Why do you hide yourself in times of trouble?
2 In arrogance the wicked persecute the poor—
let them be caught in the schemes they have devised.3 For the wicked boast of the desires of their heart,
those greedy for gain curse and renounce the Lord.
4 In the pride of their countenance the wicked say, ‘God will not seek it out’;
all their thoughts are, ‘There is no God.’
I think indeed there are forces in the world who, in the name of religion, openly mock God and attempt to crush the innocent they cannot ensnare.
Catholic Sensibility 
There are a number of Palestinian Gandhis as well as Israeli Gandhis – women and men who promote nonviolence. There is a Palestinian center in Bethlehem that promotes nonviolence and there are a number of Israelis who also promote nonviolence and interchanges among Israelis and Palestinians, among Jews, Christians, and Muslims.
I don’t have more information immediately available to me but if anyone is interested I can do some research and share it.