Edwin Frederick O'Brien

In 2009, O'Brien criticized the lack of "respect for human dignity for each of its members" from the Legion

LGBTQ In 2005, O'Brien expressed his personal opposition to admitting gay men to seminaries, a position he said was "based on 12 years' experience as rector of two U.S. seminaries".

O'Brien led a successful campaign in 2011 to defeat a bill in the Maryland General Assembly to legalize same-sex marriage.

Just War

O'Brien has been an outspoken proponent of the just war theory. Sometimes called the "Warrior Cardinal", he is seen as a controversial figure and is considered to have given moral justifications for the 2003 US invasion in Iraq. Early in 2003, O'Brien spoke to Catholic members of the corps of cadets at the United States Military Academy at West Point during a mass: "I know that a lot of people have said that the Pope is against war with Iraq ... But even if he did, you are not bound by conscience to obey his opinion. However, you are bound in conscience to obey the orders of your Commander-in-Chief, and if he orders you to go to war, it is your duty to go to war". In March 2003, a few days after the Iraq invasion, in a letter to American Catholic military chaplains, O'Brien wrote: "Given the complexity of factors involved, many of which understandably remain confidential, it is altogether appropriate for members of our armed forces to presume the integrity of our [military] leadership and its judgments, and therefore to carry out their military duties in good conscience ... It is to be hoped that all factors which have led to our intervention will eventually be made public, and ... will shed helpful light upon our President's decision". O'Brien did not endorse the Iraq war or the motivations behind it. Supporters of the war in Iraqi cited his positions. He was criticized in 2003 and 2004 by opponents of the war for distancing himself from the pope's position and that of the U.S. Conference of Catholic Bishops.

According to the journalist Sabrina Ferrisi in a 2009 article, O'Brien's spiritual direction proved effective in calming the doubts of soldiers, advising them that they can safely leave the responsibility for moral decision-making to the US Government. O'Brien believes that chaplains play an essential role in helping soldiers perform their fighting duties with a clear conscience, and in easing relationships with local populations and to avoid such gross misconduct as the torture of prisoners at the Abu Ghraib prison in Iraq.

In July 2009, at the U.S. Strategic Command Deterrence Symposium, O'Brien provided his view on just war theories, saying "The moral end we seek ought to shape the means we use", that the U.S. must "move beyond nuclear deterrence as rapidly as possible". He urged world leaders to "stay focused on the destination of a nuclear-weapons-free world and on the concrete steps that lead there."

O'Brien in 2010 complained that too few Catholics priests were serving in active duty, being replaced by chaplains of other faiths because the military disregarded the significance of denominational affiliation.

In September 2013, when Obama was considering the use of military force against the Bashar al-Assad regime in Syria, O'Brien said that "whatever we do will contribute to peace in that part of the world". This position contradicted the views of the hierarchy of the Catholic Church in Syria.

Immigration O'Brien in 2011 expressed his support of the Maryland DREAM Act, which provided free college tuition to certain undocumented immigrants. During a meeting on immigration that was sponsored by the Archdiocese of Chicago in 2012, O'Brien made these remarks;We acknowledge that our nation must protect and keep its borders. But we also suggest a more fundamental principle that when the basic needs of a person do not find an answer in their own country, these persons have the right to seek a solution outside, in order to support themselves and their families.

Middle East In 2018, O'Brien criticized a bill passed by the Israeli Knesset that removed Arabic as an official language in Israel and allowed majority-Jewish communities to discriminate against Israeli Arabs in housing.