One of the sites of the jihadists’ terror was the mausoleum of Ayatollah Ruhollah Khomenei, the founder of both the Islamic revolution and the republic it gave birth to, a figure revered by both conservatives and reformists in Iran’s Islamic political structure. Khomeini’s political ideology, known in Farsi as “velayat-e-faqih,” or guardianship of a supreme jurist, is a uniquely Shiite concept. By its very nature, it conflicts with Sunni beliefs and especially Wahhabism, the ideology that all the terror groups inflicting misery on Afghanistan, Iraq and Syria — as well as London, Paris and Brussels — adhere to. The political concept is that in the absence of the Messiah, a qualified jurist cleric — an ayatollah for Shiites — must be the guardian over the Muslim faithful, thus the position of Supreme Leader in Iran; the Shiite interpretation is anathema to fundamentalist Sunnis’ worldview.

To attempt to blow up the resting place of the father of the velayat — a conspicuously huge structure on the outskirts of Tehran — and to kill Shiites from different countries who had come to pay their respects to Khomeini is hugely symbolic for the Islamic State’s supporters. But it pleases Wahhabists everywhere. Saudi Arabia’s deputy crown prince, Mohammed bin Salman, recently declared that there is no point in talking to Iran because the country adheres to an “extremist ideology,” seemingly a reference to velayat.

Prince Mohammed also threatened to ensure that “the battle is for them in Iran,” which many Iranians, including the government, took as a military threat. Indeed, already in Tehran, and in spite of the Islamic State’s claim of responsibility, some Iranian fingers (especially military ones) are pointing to Saudi Arabia. Many Iranians, no strangers to conspiracy theories, will believe Saudi complicity at best and direct instructions at worst. This will only exacerbate tensions between the Middle East’s two behemoths, who are already battling it out in Syria and Yemen. It is also likely to put further strain on the relationship between Iran and the United States, where an uneasy truce left over from the Obama administration has been threatened by the Trump administration and Congress’s saber rattling, as well as the president’s recent sword dance in the Arabian desert.

The other location of the terrorist attacks, Iran’s Parliament building — which has symbolized Iranians’ democratic aspirations since the constitutional revolution of 1906 — was also certainly chosen for its symbolic significance.