In the fifty years after World War II, the United States and western Europe generally maintained close diplomatic relations. Though they were never in total agreement, they usually worked together to promote international consensus under U.S. guidance, as represented by the NATO alliance. For example, a U.S.-led coalition that included thousands of troops from France and the United Kingdom and smaller contributions from other NATO allies attacked Iraqi forces in Kuwait in the 1990–1991 Persian Gulf War, freeing the small nation from attempted annexation by Iraqi dictator Saddam Hussein. Over time, however, the growing power of the European Union and the new unilateral thrust of Washington’s foreign policy created strains in traditional transatlantic relations.

The growing gap between the United States and Europe had several causes. For one, the European Union was now the world’s largest trading block, challenging the predominance of the United States. Prosperous European businesses invested heavily in the United States, reversing a decades-long economic relationship in which investment dollars had flowed the other way. For another, under Presidents George W. Bush (r. 2001–2009) and Barack Obama (r. 2009– ), the United States often ignored international opinion in pursuit of its own interests. Citing the economic impact, Washington refused to ratify the Kyoto Protocol of 1997, which was intended to limit global warming and which had been agreed to by nearly two hundred countries. Nor did the United States join the International Criminal Court, a global tribunal meant to prosecute individuals accused of crimes against humanity, which nearly 140 states agreed to join. These positions troubled EU leaders, as did unflagging U.S. support for Israel in the ongoing Palestinian-Israeli crisis.

A values gap between the United States and Europe contributed to cooler relations as well. Ever more secular Europeans had a hard time understanding the religiosity of many Americans. Relatively lax gun control laws and use of capital punishment in the United States were viewed with dismay in Europe, where most countries had outlawed private handgun ownership and abolished the death penalty. Despite Obama’s health-care reforms — which evoked controversy among Americans — U.S. reluctance to establish a single-payer, state-funded program surprised Europeans, who saw their own such programs as highly advantageous.

Hardball geopolitical issues relating to NATO further widened the gap. The dissolution of the Communist Warsaw Pact left NATO without its Cold War adversaries. Yet NATO continued to expand, primarily in the territories in the former East Bloc — the defensive belt the Soviet Union had established after World War II. NATO’s expansion angered Russia’s leaders, particularly when President Bush moved to deploy missile defense systems in Poland and the Czech Republic in 2008. Even within the alliance there were tensions. By 2009, with twenty-eight member states, it was difficult to shape unanimous support for NATO actions. France, for example, did not support NATO’s engagement in Bosnia in 1995 (see page 1015) because the alliance failed to get UN approval for the action, and in 2011 Germany and Poland refused to back NATO air strikes against the Libyan regime (see page 1034). As the EU expanded, some argued that Europe should determine its own military and defense policy without U.S. or NATO guidance.

American-led wars in Afghanistan and Iraq, undertaken in response to the September 11 terrorist attacks against the United States, further strained U.S.-European relations. On the morning of September 11, 2001, passenger planes hijacked by terrorists destroyed the World Trade Center towers in New York City and crashed into the Pentagon. Perpetrated by the radical Islamist group al-Qaeda, the attacks took the lives of more than three thousand people from many countries and put the personal safety of ordinary citizens at the top of the West’s agenda.

Immediately after the September 11 attacks, the peoples and governments of Europe and the world joined Americans in heartfelt solidarity. Over time, however, tensions between Europe and the United States re-emerged and deepened markedly, particularly after President Bush declared a unilateral U.S. war on terror — a determined effort to fight terrorism in all its forms, around the world. The main acts in Bush’s war on terror were a U.S.-led war in Afghanistan, which started in 2001, and another in Iraq, which lasted from 2003 to 2011. Both succeeded in quickly bringing down dictatorial regimes. At the same time, they fomented anti-Western sentiment in the Muslim world and failed to stop regional violence driven by ethnic and religious differences (see “Europe and Its Muslim Citizens”).

The U.S. invasion of Iraq and subsequent events caused some European leaders, notably in France and Germany, to question the rationale for and indeed the very effectiveness of a “war” on terror. Military victory, even over rogue states, would hardly end terrorism, since terrorist groups easily moved across national borders. Terrorism, they concluded, was better fought through police and intelligence measures. Europeans certainly shared U.S. worries about stability in the Middle East, and they faced their own problems with Islamist terrorism, especially after the Madrid and London train bombings of 2004 and 2005. But European leaders worried that the tactics used in the war, exemplified by Washington’s readiness to use its military without international agreements or UN backing, violated international law.

American conduct of the war on terror also raised serious human rights concerns. The revelation of the harsh interrogation techniques used on prisoners held by American forces and abuse of prisoners in Iraq shocked many Europeans. U.S. willingness to engage in “extraordinary rendition” — secretly moving terrorism suspects to countries that allow coercive interrogation techniques — caused further concern.

The election of Barack Obama, America’s first African American president, in 2008, and his re-election in 2012, brought improvement to U.S.-European foreign relations. Upon election, President Obama announced that he would halt deployment of missiles in central Europe and reduce nuclear arms, easing tensions with Russia. He took U.S. troops out of Iraq in 2011, promised to withdraw U.S. combat troops from Afghanistan in 2014, and quietly shelved the language of the “war on terror.” In February 2013 the president’s call for a free-trade agreement with the European Union, which would end tariffs and regulatory barriers to trade, raised hopes for closer economic and political cooperation in the future. Despite these changes, many Europeans continued to find U.S. willingness to undertake unilateral military action disturbing — American drone attacks on suspected terrorists along the Afghanistan-Pakistan border were particularly unpopular.11 In the long run, though ties with the United States remained solid, European states increasingly responded independently to global affairs.