"To the leaders present, I make a heartfelt appeal for them to help find ways to overcome the conflicting positions and to lay aside the futile pursuit of a military solution," the Pope wrote. "Rather, let there be a renewed commitment to seek, with courage and determination, a peaceful solution through dialogue and negotiation of the parties, unanimously supported by the international community."
The Pope's letter came as world leaders arrived for a two-day summit that was intended to focus on the world economy but now will be dominated by the looming threat of U.S. intervention in Syria. Congress will vote early next week on whether to support President Barack Obama's call for air strikes on military targets in retaliation for a chemical weapons attack allegedly directed by the Syrian regime of Bashar al-Assad that killed 1,429 people, including hundreds of children.
The Pope has strongly opposed escalation of the violence in Syria and has proclaimed Sept. 7 as a day of fasting and prayer for peace. He will lead a vigil in St. Peter's Square and has asked churches around the world to join him.
In his letter to Putin, Pope Francis acknowledged that economic matters were the primary purpose of G-20 meetings but said world leaders "cannot remain indifferent to the dramatic situation in Syria" and that economic prosperity and peace go hand in hand.
"The world economy will only develop if it allows a dignified way of life for all human beings, from the eldest to the unborn child, not just for citizens of the G-20 member states but for every inhabitant of the Earth, even those in extreme social situations or in the remotest places," the Pope wrote.
"From this standpoint, it is clear that . . . armed conflicts are always a deliberate negation of international harmony, and create profound divisions and deep wounds which require many years to heal. Wars are a concrete refusal to pursue the great economic and social goals that the international community has set itself.
"Without peace, there can be no form of economic development. Violence never begets peace, the necessary condition for development."
The Pope also reminded G-20 leaders of their "moral duty" to provide humanitarian aid to "those suffering because of the conflict, both within and beyond the country’s borders."
His letter came a day after the Jesuit Superior General, Fr. Adolfo Nicolas, said that military action against Syria by U.S. and French forces would be an abuse of power.
"I have to confess that I cannot understand who gave the United States or France the right to act against a country in a way that will certainly increase the suffering of the citizens of that country, who, by the way, have already suffered beyond measure," Nicolas said on Vatican Radio.
"Violence and violent action, like what is being planned, have to always be the last resort and administered in such a way that only the guilty are affected. In the case of a country this is evidently impossible to control and, thus, it seems to me totally unjustified.
"We, Jesuits, support 100 per cent the Holy Father and wish with all our hearts that the threatened attack on Syria does not take place."
Nicolas said the military action being contemplated by the United States is unjustified because there is insufficient evidence to prove the chemical attacks were ordered by the Syrian government and also because air strikes will likely cause more civilian suffering.
"With all respect for the people of the United States, I think that a military intervention like the one being planned is itself an abuse of power," he said. "The U.S. has to stop acting and reacting like the big boy of the neighbourhood of the world. This leads inevitably to abuse, harassment and bullying of the weaker members of the community."