Overall, Bush tended to be Clinton's antithesis. Early in his presidency, he worked to involve other nations minimally, in sharp contrast to the Clinton administration's multilateralism. In this and other policies, the Bush administration opted to abandon the Kyoto Protocol, a legal agreement proposed by European nations to cut down the pollution blamed for global warming. Bush also worked to dissolve the Anti-Ballistic Missile Treaty (ABM) with Russia. Displeased by these maneuvers, some European and Asian allies called Bush's foreign policies "cowboy diplomacy." Concerns lingered over trade issues, North and South Korea, and what some considered Bush's refusal to engage in the Middle East. By mid-2002, as suicide bombings increased and tensions escalated as a result, Bush was forced to take a stand; he called for the creation of a provisional Palestinian state, predicated on the installation of a new leader to replace Yasser Arafat.
When a U.S. spy plane doing routine surveillance near China's southern coast was hit by a Chinese fighter aircraft, the Bush administration was able to resolve the issue with the Chinese government through a careful apology, short of a humiliating surrender. Bush also made a quick friend of Mexican president Vicente Fox, and he forged warm relations with Russian President Vladimir Putin. Despite their inability to agree about the ABM treaty, Bush and Putin signed a new treaty reducing nuclear missiles.
The defining moment of Bush's presidency and one that profoundly redefined his approach to foreign affairs, occurred on 11 September 2001, when suicide bombers sent two commercial airplanes into New York City's World Trade Center Towers, one airplane into the Pentagon in Washington D.C., and one into a field near Pittsburgh, Pennsylvania. These events killed thousands in a single day and brought a death toll on American soil unheard of since the Civil War.
In a speech to Congress nine days later Bush said: "Every nation in every region now has a decision to make. Either you are with us, or you are with the terrorists." This approach became known as the Bush Doctrine on anti-terrorism.
As Bush set forth to punish the perpetrators, he became immensely popular among Americans. His administration built a coalition of 120 countries to capture those suspected of directing the attacks: Osama bin Laden, the al-Qaeda network, and Bin Laden's Taliban protectors in Afghanistan. By December 2001, following a U.S.-led military campaign, the Taliban had collapsed and an interim government was installed in Afghanistan.
On a grand scale, countries worked to stop the movement of terrorists. The United Nations Security Council unanimously passed Resolution 1373, which called on all member states to join the struggle against international terrorism and allowed for the coalition's military intervention in Afghanistan. Some member nations detained suspects, while others offered the U.S. military assistance and overflight rights. For the first time, NATO invoked Article 5, which declares an attack on one member as an attack on all. NATO surveillance aircraft were deployed to patrol American skies, Japan sent a warship to the Arabian Sea and Germany sent ground troops outside Europe, which had not been done since World War II.
The Bush doctrine came under severe strain in 2002 as tensions in the Middle East escalated to the brink of war. A series of deadly Palestinian suicide bombings targeted against the Israeli civilian population prompted a brutal and sustained military response by the Israeli Defense Force. Thousands of suspected terrorists were arrested and the infrastructure of the West Bank was reduced to rubble. The violence is considered by many to be a root cause of much anti-American sentiment in the Arab world and Europe. In 2003, President Bush stood firmly behind the so-called "road map," a plan for peace in Israel and the occupied territories drafted by the United States, European Union (EU), Russia, and the UN (the "quartet"). The Palestinian Authority named Mahmoud Abbas prime minister, a man with whom Israeli Prime Minister Ariel Sharon stated he would negotiate.
President Bush led the United States to war with Iraq on 19 March 2003. In the prelude to the outbreak of hostilities, Bush and British prime minister Tony Blair were faced with opposition within the UN Security Council—primarily led by France, Germany, and Russia—to the passage of a resolution authorizing the use of force against the Saddam Hussein regime if it did not disarm itself immediately of weapons of mass destruction. The UN Security Council had passed Resolution 1441 in November 2002, allowing for the reintroduction of weapons inspectors; however, the Bush administration doubted their effectiveness and thus called for more severe measures to be taken. Baghdad fell to U.S. forces on 9 April (southern Iraq had been secured by British troops), and on 1 May, Bush declared major combat operations had ceased and that the United States and its allies had prevailed. Coalition forces were then occupied with the task of restoring order and basic services such as electricity and running water to the country. As of mid-2003, the United States had appointed a civilian administrator for Iraq, and plans for the creation of an interim government were being made. In addition to guiding the transition to a legitimate government and stable society in Iraq, Bush is also faced with repairing the damage done to diplomatic relations within the trans-Atlantic Western alliance.
As suicide bombings against Western targets continued around the globe in 2002–03, Bush asserted stepped-up measures needed to be taken against international terrorism.
In his 2003 State of the Union Address, President Bush pledged $15 billion to fight HIV/AIDS in Africa and the Caribbean. Such outreach to regions of the world which normally do not enjoy the same level of attention with regard to U.S. foreign policy as other, more high-profile crises, was seen as both surprising and generous on the part of Bush.