John Bolton, former U.S. ambassador to the UN and vocal critic of the Obama administration, is often sought after by the media for his opinion on foreign policy issues, but his stake in the presidential election -- as a foreign policy adviser to Mitt Romney -- is rarely, if ever, disclosed by the outlets that publish him.

In addition to editorials in The Wall Street Journal, The Washington Times, and appearances on Fox News that left Bolton's ties to Romney undisclosed, a Media Matters review found editorials in five additional publications written or co-written by Bolton that left out that key information.

In total, Bolton wrote seven editorials that were critical of Obama's policies for The New York Times, Christian Science Monitor, The Washington Examiner, The Weekly Standard and the National Review after he became affiliated with the Romney campaign. None of those op-eds identified Bolton as a member of the Romney team. However, three of those outlets -- the Times, Monitor, and the Examiner -- have reported separately on Bolton's position in the campaign.

The New York Times' non-disclosure: One op-ed.

The Times covered Bolton's endorsement of Mitt Romney on January 12, and labels Bolton as a campaign foreign policy adviser for Romney in a June 27 article.

• On March 8, Bolton co-authored an editorial with John C. Yoo on space policy, which largely criticizes the U.S. policy of following Europe's code of conduct for regulating outer space.  The authors accuse Obama of “circumvent[ing] the Senate's central constitutional role in making treaties” and “eroding American sovereignty on the sly.”

The Times identifies Bolton as a senior fellow at the American Enterprise Institute and an ambassador to the UN from 2005 to 2006.

The Christian Science Monitor's non-disclosure: Two op-eds.

In its news coverage, the Monitor cites Bolton as a Romney adviser on September 15.

• In an April 3 op-ed, Bolton is critical of Obama's position toward Israel, stating “the Obama administration appears to be conducting a campaign of leaks to the media to stop Israel from attacking Tehran's nuclear program.”  He is identified as a senior fellow at the American Enterprise Institute and U.S. ambassador to the United Nations in 2005 and 2006.
• On February 10, Bolton wrote a piece with Congressman Edward Markey on Obama's nuclear proliferation policy. They write: "[the Obama administration] recently announced a change of course that will enable more nuclear weapons to end up in the hands of unstable regimes." The piece describes Bolton as a senior fellow at the American Enterprise Institute, and having previously served as U.S. ambassador to the UN and Undersecretary of State for Arms Control and International Security.

The Washington Examiner's non-disclosure: One op-ed.

In a January 11 blog post, editorial page editor David Freddoso noted that Bolton would be joining the Romney campaign.

• In a June 12 editorial on intelligence leaks, Bolton says of the president, “Obama has proclaimed, with both his typical narcissism and moral superiority, that 'the notion that my White House would purposely release classified national security information is offensive,' ” and calls Obama's image “one of the few political bright spots for the embattled president.” 

The paper notes that Bolton is a former U.S. ambassador to the UN, senior fellow at the American Enterprise Institute, and the author of Surrender Is Not an Option: Defending America at the United Nations and Abroad. [Examiner, June 13, 2012, via Nexis]

The Weekly Standard's non-disclosure: Two op-eds.

• On July 16, Bolton wrote on the “ongoing failure of talks concerning Iran's nuclear weapons program,” and is critical of both Obama and Bush. He says that “sanctions could help destabilize Tehran, but unfortunately both the Obama and Bush administrations have failed on that score.”
• In a column on February 20, he claims Obama “apparently cannot comprehend threats like Syria and Iran.” 

The Weekly Standard identifies Bolton as an ambassador to the UN from 2005 to 2006, and a senior fellow at the American Enterprise Institute.

The National Review's non-disclosure: One op-ed.

• In a June 25 editorial, Bolton strategizes options for a U.S. intervention in Syria, and slams the “current administration policy, which has stumbled from failure to failure over the past year.” He also makes clear his preferred outcome for the presidential election, when he asks if “Obama wakes up to reality -- or, more likely, the conflict in Syria drags on until Governor Romney's January 20, 2013, inauguration -- what should we conclude the United States ought to do?”

The National Review identifies Bolton as a former U.S. ambassador to the UN, a senior fellow at the American Enterprise Institute, and the author of Surrender Is Not an Option: Defending America at the United Nations and Abroad.

 Note: Media Matters checked the identification of Bolton through the publication's website and Lexis Nexis.