Robert Charles O'Brien Jr.[1][2] (born June 18, 1966)[1] is an American attorney who was the twenty-seventh United States national security advisor from 2019 to 2021.

[3] O'Brien was born in Los Angeles and raised in Santa Rosa, California, where he attended Cardinal Newman High School.

[5] He received a Bachelor of Arts in political science from the University of California, Los Angeles in 1989, and a Juris Doctor from the UC Berkeley School of Law in 1992.

[11] O'Brien was nominated by President George W. Bush as the U.S. alternate representative to the 60th session of the United Nations General Assembly during 2005–06.

[17] During the time he advised Cruz's presidential campaign, he said: "It's clear that Vladimir Putin just doesn't like [Hillary Clinton], and is going to do what he can to help Donald Trump.

[24] As envoy for hostage affairs, O'Brien attended the trial of the American rapper ASAP Rocky, on assault charges, in Stockholm, Sweden, telling reporters, "The president sent me here, so it's totally appropriate.

[26] The Swedish government and court rejected political pressure in the case, citing rule-of-law principles; the rapper was ultimately convicted of assault, and sentenced to time served.

[27] In 2018, as envoy for hostage affairs, O'Brien helped obtain the release of American pastor Andrew Brunson, who had been held prisoner for two years in Turkey, raising U.S.-Turkish tensions.

[28] O'Brien was also involved in obtaining the release of Danny Burch, an American oil worker held in Yemen for a year, and who ultimately received an Oval Office meeting with President Trump.

[31] A few days later, O'Brien announced that Matthew Pottinger would become the deputy national security advisor,[32] replacing Charles Kupperman in that role.

[34] In December 2019, O'Brien defended Trump's decision to pardon Navy SEAL Eddie Gallagher, who was accused by several fellow Navy SEAL members of his platoon of shooting unarmed civilians who posed no threat and of murdering an injured 17-year-old ISIS fighter, but who was convicted of only "wrongfully posing for an unofficial picture with a human casualty".

[35][36] After the Trump administration's January 2020 drone strike against Qasem Soleimani, the head of the Iranian Islamic Revolutionary Guard Corps and commander of its Quds Force, O'Brien defended the intelligence the administration used to justify the killing, arguing that Soleimani had been planning attacks on U.S. military and diplomatic installations in Iraq and elsewhere in the Middle East.

[38] He threatened sanctions against China if it moved to pass a national security law that pro-democracy activists believed would undermine freedom in Hong Kong.

"[42] In the same speech, he asserted: "Together with our allies and partners, we will resist the Chinese Communist Party's efforts to manipulate our people and our governments, damage our economies, and undermine our sovereignty.

"[51][52][53] Chad Wolf, who was acting secretary of the Department of Homeland Security, alleged that O'Brien had suppressed assessments of Russian interference.

[68] On March 21, 2023, Taiwanese President Tsai Ing-wen presented O'Brien with the Order of Brilliant Star with Special Grand Cordon, in recognition of his contributions to Taiwan-US relations.

Former Republican National Committee (RNC) chair Michael Steele questioned O'Brien's viability as a candidate given his lack of name recognition or distinct electoral niche.

[74] An article published in The American Conservative suggested that O'Brien's reported presidential aspirations are a way to build his stature for a future appointment as Secretary of State or Secretary of Defense, adding: "O'Brien remains in Trump's good graces, as well as staying in good standing in Washington's foreign policy community.

A former colleague from the George W. Bush administration, Runde summarized O'Brien's views as follows: Robert writes from a series of beliefs and assumptions that I also hold: a deep belief in American Exceptionalism, that peace comes through strength, that the United States is stronger when it partners with its allies and when America is a reliable friend to its allies, that the greatness of America comes from a people that respect tradition and the rule of law, and that (yes) we are the good guys and there are some bad guys out there.

Alex Ward, the associate director in the Atlantic Council's Brent Scowcroft Center on International Security, noted that "O'Brien's book is frustrating because it starts with the assumption that all of Obama's foreign policy choices are bad and assumes the reader believes this as well...[H]is analysis, while passionately and decently argued, missed the bigger picture through the partisan fog.