Joe Biden chairs US Senate Committee on Foreign Relations

Biden was also a long-time member of the U.S. Senate Committee on Foreign Relations.

In 1997, he became the ranking minority member and chaired the committee from June 2001 through 2003. When Democrats re-took control of the Senate following the 2006 elections, Biden again assumed the top spot on the committee in 2007. Biden was generally a liberal internationalist in foreign policy. He collaborated effectively with important Republican Senate figures such as Richard Lugar and Jesse Helms and sometimes went against elements of his own party. Biden was also co-chair of the NATO Observer Group in the Senate. A partial list covering this time showed Biden meeting with some 150 leaders from nearly 60 countries and international organizations. Biden held frequent hearings as chair of the committee, as well as holding many subcommittee hearings during the three times he chaired the Subcommittee on European Affairs.
During his first decade in the Senate, Biden focused on arms control issues. In response to the refusal of the U.S. Congress to ratify the SALT II Treaty signed in 1979 by Soviet leader Leonid Brezhnev and President Jimmy Carter, Biden took the initiative to meet the Soviet Foreign Minister Andrei Gromyko, educated him about American concerns and interests, and secured several changes to address objections of the Foreign Relations Committee. When the Reagan administration wanted to interpret the 1972 SALT I Treaty loosely in order to allow the Strategic Defense Initiative to proceed, Biden argued for strict adherence to the treaty's terms. Biden clashed again with the Reagan administration in 1986 over economic sanctions against South Africa, leading to a heated exchange between the senator and Secretary of State George P. Shultz.
Biden became interested in the Yugoslav Wars after hearing about Serbian abuses during the Croatian War of Independence in 1991. Once the Bosnian War broke out, Biden was among the first to call for the "lift and strike" policy of lifting the arms embargo, training Bosnian Muslims and supporting them with NATO air strikes, and investigating war crimes. Both the George H. W. Bush administration and Clinton administration were reluctant to implement the policy, fearing Balkan entanglement. In April 2003, Biden spent a week in the Balkans and held a tense three-hour meeting with Serbian leader Slobodan Milošević. Biden related that he told Milošević, "I think you're a damn war criminal and you should be tried as one."Biden wrote an amendment in 1992 to compel the Bush administration to arm the Bosnians, but deferred in 1994 to a somewhat softer stance preferred by the Clinton administration, before signing on the following year to a stronger measure sponsored by Bob Dole and Joe Lieberman. The 1995 NATO bombing campaign in Bosnia and Herzegovina then led to the Dayton Agreement and a successful NATO peacekeeping effort. Biden has called his role in affecting Balkans policy in the mid-1990s his "proudest moment in public life" that related to foreign policy. In 1999, during the Kosovo War, Biden supported the NATO bombing campaign against Serbia and Montenegro, and co-sponsored with his friend John McCain the McCain-Biden Kosovo Resolution, which called on President Clinton to use all necessary force, including ground troops, to confront Milosevic over Serbian actions in Kosovo. In 1998, Congressional Quarterly named Biden one of "Twelve Who Made a Difference" for playing a lead role in several foreign policy matters, including NATO enlargement and the successful passage of bills to streamline foreign affairs agencies and punish religious persecution overseas.

Biden had voted against authorization for the Gulf War in 1991, siding with 45 of the 55 Democratic senators; he said the U.S. was bearing almost all the burden in the anti-Iraq coalition. Biden stated in 2002 that Saddam Hussein was a threat to national security, and that there was no option but to eliminate that threat. The Bush administration rejected an effort Biden undertook with Senator Richard Lugar to pass a resolution authorizing military action only after the exhaustion of diplomatic efforts. In October 2002, Biden voted in favor of the Authorization for Use of Military Force Against Iraq, justifying the Iraq War. While he soon became a critic of the war and viewed his vote as a "mistake", he did not push to require a U.S. withdrawal. He supported the appropriations to pay for the occupation, but argued repeatedly that the war should be internationalized, that more soldiers were needed, and that the Bush administration should "level with the American people" about the cost and length of the conflict.
By late 2006, Biden's stance had shifted, and he opposed the troop surge of 2007. Biden was instead a leading advocate for dividing Iraq into a loose federation of three ethnic states. In November 2006, Biden and Leslie H. Gelb, President Emeritus of the Council on Foreign Relations, released a comprehensive strategy to end sectarian violence in Iraq. Rather than continuing the present approach or withdrawing, the plan called for "a third way": federalizing Iraq and giving Kurds, Shiites, and Sunnis "breathing room" in their own regions. In September 2007, a non-binding resolution passed the Senate endorsing such a scheme. Iraq’s political leadership united in denouncing the resolution as a de facto partitioning of the country, and the U.S. Embassy in Baghdad issued a statement distancing itself.
In March 2004, Biden secured the brief release of Libyan democracy activist and political prisoner Fathi Eljahmi, after meeting with leader Muammar al-Gaddafi in Tripoli. In May 2008, Biden sharply criticized President George W. Bush for his speech to Israel's Knesset in which he suggested that some Democrats were acting in the same way some Western leaders did when they appeased Hitler in the runup to World War II. Biden stating that "This is bullshit. This is malarkey. This is outrageous. Outrageous for the president of the United States to go to a foreign country, sit in the Knesset ... and make this kind of ridiculous statement." Biden later apologized for using the expletive. Biden further stated that "Since when does this administration think that if you sit down, you have to eliminate the word 'no' from your vocabulary?"

He chaired the Senate Foreign Relations Committee and sits on the Senate Judiciary Subcommittee on Terrorism, Technology and Homeland Security. Biden ran for the Democratic presidential nomination in 1988. His campaign was tainted, however, when he was accused of plagiarizing a stump speech from a British Labour Party leader.

He returned to the Senate to become a prominent foreign policy voice in the 1990s, particularly on the Balkans conflicts. He has traveled to the region many times and was a proponent for U.S. intervention there. Biden has also been a strong advocate for nuclear nonproliferation efforts.
Biden's proposal for resolving the conflict in Iraq continued to generate discussion late into 2007. Biden, along with CFR President Emeritus Leslie H. Gelb, back creation of a federal state in Iraq with Kurdish, Sunni, and Shia autonomous regions. Biden was also one of the only candidates to support using U.S. ground forces to end the conflict in Sudan’s Darfur region.
Before being selected as Obama’s running mate, Biden ran for the Democratic nomination, dropping out of the race in January 2008.