He is now a partner at the Washington, D.C. law firm Arnold & Porter,[2] and Adjunct Senior Fellow at the Council on Foreign Relations.

[8] After 9/11, Bellinger,[9] and Rice[10] were excluded by other officials in the administration from the preparation of President Bush's order establishing military commissions.

[14] He helped persuade the White House to support the Detainee Treatment Act of 2005 (the McCain Amendment) and to close the secret CIA black sites in 2006.

[20] In 2006, Bellinger headed the U.S. delegation that negotiated the Third Additional Protocol to the Geneva Conventions that allowed the humanitarian aid societies of Israel and the Palestinian territories to join the International Red Cross/Red Crescent Federation.

[22] In a series of speeches,[23] Bellinger said the United States was prepared to assist the Court's investigation in Sudan even if it did not intend to join the Rome Statute.

[24] He has urged Congress to amend the American Servicemembers Protection Act to allow the United States to provide more support to the Court in certain war crimes investigations.

[25] In 2008, Bellinger represented the United States before the International Court of Justice (ICJ) in a case filed by Mexico after the Supreme Court in Medellin v Texas invalidated President Bush's February 2005 order directing courts in Texas and other states to comply with the ICJ's 2004 order in Case Concerning Avena and Other Mexican Nationals that the United States review the convictions and death sentences of a group of Mexican nationals who had not been notified of their right to consular access under the Vienna Convention on Diplomatic Relations.

He later testified before Congress in support of legislation that would allow federal courts to review the death sentences of foreign nationals who had not been notified of their rights to consular access.

[33] In testimony before Congress in 2012, he urged the Obama administration to do more to explain the legality of targeted killings and to make its drone program more transparent.

[34] In 2013, Bellinger was a signatory to an amicus curiae brief submitted to the Supreme Court by a group of former Republican officials in support of same-sex marriage in Hollingsworth v.

[36] In November 2018, Bellinger joined a group formed by George Conway, "Checks and Balances," composed of more than a dozen members of the conservative-libertarian Federalist Society, which had been instrumental in selecting candidates for the Trump administration to appoint to federal courts.

"[37] In August 2020, Bellinger was one of 70 former senior security officials who took out a full-page ad in the Wall Street Journal, saying they would vote for Joe Biden as president.