The head of the U.S. bishops' international justice and peace committee implored Secretary of State John Kerry to utilize U.S. foreign policy to address the "root causes" of child migration from Central America.

"The crisis on our borders will not be minimally resolved until drugs and arms flows, harmful trade provisions, and other critical economic policies that contribute to violence are addressed and rectified," wrote Bishop Richard E. Pates of Des Moines in a July 24 letter to Secretary Kerry.

Bishop Pates wrote the letter after his "solidarity trip" to Guatemala, El Salvador, and Honduras, the origin countries of many of the child migrants coming to the U.S.

He outlined the root causes of migration there – violence at home, human and drug trafficking, and lack of economic opportunity – and asked Secretary Kerry to focus more on U.S. investment in education and jobs than on military assistance in order to spur a "long term resolution" to the problems.

The number of unaccompanied child migrants to the U.S. has doubled each year since 2011. An estimated 90,000 will have come by the end of this fiscal year, and in 2015 the number is expected to rise to 145,000, according to U.S. officials.

Bishop Pates blamed the exploitative practices of multi-national mining corporations, the over-militarization of U.S. assistance, and current trade agreements for the economic and social hardships that are driving migration.

"My brother bishops in Central America have urged us to encourage alternatives to militarization of U.S. assistance and instead emphasize economic opportunity," he wrote. "The United States must recognize our own contributions to this crisis, and support more effective programs that reduce drug usage here at home."

Current trade policies like the Central American Free Trade Agreement (CAFTA) are suffocating small businesses in those countries, the bishop continued.

"As an example, U.S. corporations, receiving significant subsidies and other protections from our government, have been able to export corn and other agricultural products to Central America, driving down local prices for these products and forcing rural families off their lands," he explained.

And U.S. and Canadian mining companies are harming the environment and public health in those countries and forcibly silencing opposition to their practices, he added.

"We heard powerful testimonies, by civil and Church leaders, of brutality and oppression, including torture and murder. Community leaders and representatives of indigenous communities in El Salvador, Guatemala and Honduras, who resisted the unregulated expansion of mining activities in their native lands, have been targeted," Bishop Pates wrote.

The U.S. government must ensure that that companies abide by the same "standards of care for human life and ecology" abroad as they do in the U.S. and Canada, he said.

All these problems are behind the increase in migration, the bishop underscored, and the U.S. must address them to solve the current crisis in the long-term.

"We must recognize that there are correlations between these harmful trade practices and the deplorable conditions that lead to poverty, increased unemployment (especially among the young), violence, trafficking and the resultant push for migration," he concluded.