Can small changes produce larger effects long term?-yes. Like the prophet Mohammad taught that to unite the world first one needs to unite the differences in his land-unite his land. I also like the Popes effort in going to Muslim countries and praising Islam.
A reporter goes to Jerusalem and visits the Wailing Wall where he sees an old man praying. He respectfully waits till he's finished, then interviews him. The old man says he has been praying there for 60 years.
"What do you pray for?"
"I pray for love, peace and unity between Jews, Muslims and Christians"
It would seem the pope is on a collision course with the Israel Government. He attacked the holocaust deniers, but the first thing he said was that Palestine must have it's own state, something that is unlikely to be accepted at this time.
There are few catholics in the region (less than 20,000 turned up for yesterdays event) but the point of the visit is to communicate a symbolic message to a wider audience.
Language is only part of the message, the audience is only part of the message, symboilism and connections with physical and spiritual events of the past (real or imagined) is part of the message, and a declaration that there is a positive future for catholics, jews and moslems is part of the message.
If any of these messages get through prejudice to a wider audience the the visit will have been a success. There are jewish and islamic leaders who understand the message and others who do not, but the outcome will not be known for one or two generations. Religion is not a short term phenomenon.
Seed ideas are planted and allowed to grow if the soil is fertile, the human heart can be ferile ground, we will see the results in the education of children by the next genteration and the teaching in mosques and synagogues by the next generation.