The 2004 Madrid train bombings (also known in Spain as 11M) were a series of coordinated, nearly simultaneous bombings against the Cercanas commuter train system of Madrid, Spain, on the morning of 11 March 2004three days before Spain's general elections. The explosions killed 193 people and injured around 2,000. The bombings constituted the deadliest terrorist attack carried out in the history of Spain and the deadliest in Europe since 1988. The official investigation by the Spanish judiciary found that the attacks were directed by Al-Qaeda in Iraq, allegedly as a reaction to Spain's involvement in the 2003 US-led invasion of Iraq. Although they had no role in the planning or implementation, the Spanish miners who sold the explosives to the terrorists were also arrested.Controversy regarding the handling and representation of the bombings by the government arose, with Spain's two main political parties Spanish Socialist Workers' Party (PSOE) and Partido Popular (PP) accusing each other of concealing or distorting evidence for electoral reasons. The bombings occurred three days before general elections in which incumbent Jos Mara Aznar's PP was defeated. Immediately after the bombing, leaders of the PP claimed evidence indicating the Basque separatist organization ETA (Euskadi Ta Askatasuna) was responsible for the bombings, while the opposition claimed that the PP was trying to prevent the public from knowing it had been an islamist attack, which would be interpreted as the direct result of Spain's involvement in Iraq, an unpopular war which the government had entered without the approval of the Spanish Parliament.Following the attacks, there were nationwide demonstrations and protests demanding that the government "tell the truth". The prevailing opinion of political analysts is that the Aznar administration lost the general elections as a result of the handling and representation of the terrorist attacks, rather than because of the bombings per se. Results published in The Review of Economics and Statistics by economist Jose G. Montalvo seem to suggest that indeed the bombings had important electoral impact (turning the electoral outcome against the incumbent People's Party and handing government over to the Socialist Party, PSOE).

After 21 months of investigation, judge Juan del Olmo tried Moroccan national Jamal Zougam, among several others, for his participation carrying out the attack. The September 2007 sentence established no known mastermind nor direct al-Qaeda link.

Islamism (also often called political Islam or Islamic fundamentalism) is a political ideology which posits that modern states and regions should be reconstituted in constitutional, economic and judicial terms, in accordance with what is conceived as a revival or a return to authentic Islamic practice in its totality.Ideologies dubbed Islamist may advocate a "revolutionary" strategy of Islamizing society through exercise of state power, or alternately a "reformist" strategy to re-Islamizing society through grassroots social and political activism. Islamists may emphasize the implementation of sharia, pan-Islamic political unity, the creation of Islamic states, or the outright removal of non-Muslim influences; particularly of Western or universal economic, military, political, social, or cultural nature in the Muslim world; that they believe to be incompatible with Islam and a form of Western neocolonialism. Some analysts such as Graham E. Fuller describe it as a form of identity politics, involving "support for [Muslim] identity, authenticity, broader regionalism, revivalism, [and] revitalization of the community."The term itself is not popular among many Islamists who believe it inherently implies violent tactics, human rights violations, and political extremism when used by Western mass media. Some authors prefer the term "Islamic activism", while Islamist political figures such as Rached Ghannouchi use the term "Islamic movement" rather than Islamism.Central and prominent figures in 20th-century Islamism include Sayyid Rashid Rida, Hassan al-Banna, Sayyid Qutb, Abul A'la Maududi, Hasan al-Turabi,and Ruhollah Khomeini. Many Islamist movements, such as the Muslim Brotherhood, have been willing to pursue their ends by peaceful political processes, rather than revolutionary means. Others, notably Qutb, called for violence, and his followers are generally considered Islamic extremists. However, Qutb openly denounced the killing of innocents.

According to Robin Wright, Islamist movements have "arguably altered the Middle East more than any trend since the modern states gained independence", redefining "politics and even borders". Following the Arab Spring, some Islamist currents became heavily involved in democratic politics, while others spawned "the most aggressive and ambitious Islamist militia" to date, such as the Islamic State of Iraq and the Levant (ISIL).Islamism is a concept whose meaning has been debated in both public and academic contexts. The term can refer to diverse forms of social and political activism advocating that public and political life should be guided by Islamic principles. In academic usage, the term Islamism does not specify what vision of "Islamic order" or sharia is being advocated, or how the advocates intend to bring about that vision.