On Wednesday, a group of terrorists attacked the Iranian parliament building and the tomb of Ayatollah Khomeini, killing at least twelve; Islamic State (IS) has claimed responsibility. Thomas Joscelyn explains the importance of this attack:

Osama bin Laden’s organization and its spin-off, IS, have fought against Iran’s proxies in Iraq and Syria for years. Killing Shiites is a blood sport for IS’s Sunni jihadists. And Abu Bakr al-Baghdadi’s so-called caliphate reportedly has attempted to strike inside the mullahs’ country before. The group routinely agitates against the Iranians in its videos and propaganda statements. Yet it wasn’t until now that IS successfully attacked the heart of Tehran.

Al-Qaeda’s leadership long sought to rein in the anti-Shiite violence in Iraq. . . . [U]ntil 2014, [al-Qaeda in Iraq, which later became Islamic State], abided by an order from al-Qaeda’s leaders to avoid terrorist operations inside Iranian territory and against Shiites outside of Iraq. The two sides formally split in early 2014. At that point, IS [began] waging a campaign against Shiites throughout the region—and accusing al-Qaeda of being soft on them. . . .

To this day, however, al-Qaeda avoids attacks inside Iran—at least those that can be directly attributed to the organization. (It is possible that al-Qaeda supports other regional groups that occasionally target Iranian security forces on their home turf.) Files recovered during the May 2011 raid on Osama bin Laden’s compound in Abbottabad, Pakistan explain this reticence. . . .

In October 2007, bin Laden wrote a letter to [what was then known as] the Islamic State of Iraq, [in which he] disapproved of its threats against Iran [and stated that] “Iran is our main artery for funds, personnel, and communication.” Bin Laden was not against targeting Iran in principle. He simply thought the cost was too high and the benefits al-Qaeda received from the relationship were significant. The “main artery” bin Laden referenced was later targeted in a series of terrorist designations, reward offers, and other official statements by the U.S. Treasury and State Departments.

Two extraordinary events demonstrate something important about Israel’s most fervent adversaries. One was a speech given at something called The People’s Forum (funded generously by Goldman Sachs), which stated, “When the state of Israel is finally destroyed and erased from history, that will be the single most important blow we can give to destroying capitalism and imperialism.”

The suggestion that this tiny state is the linchpin of a global, centuries-old phenomenon like capitalism goes well beyond anything resembling rational criticism. Even if Israel were guilty of genocide, apartheid, and oppression—which of course it is not—it would not follow that its destruction would help end capitalism or imperialism.

The other was an anti-Israel protest that took place in front of New York City’s Memorial Sloan Kettering Cancer Center, deemed “complicit” in Israel’s evils. At organizers’ urging, participants shouted their slogans at kids in the cancer ward, who were watching from the windows. Given Hamas’s indifference toward the lives of Gazan children, such callousness toward non-Palestinian children from Hamas’s Western allies shouldn’t be surprising. The protest—like the abovementioned speech—deliberately conveyed the message that Israel is the ultimate evil and its destruction the ultimate good, cancer patients be damned.

The fact that Israel’s adversaries are almost comically perverse does not mean that they can be dismissed. If its allies fail to understand the obsessive and irrational hatred that it faces, they cannot effectively help it defend itself.