After over four years of fighting, the U.S. and its allies have finally deprived Islamic State (IS) of its territorial base in Syria and Iraq. But the presence of IS offshoots throughout Africa and Asia, and the group’s ability to carry out terrorist attacks—for instance the Easter bombings in Sri Lanka—show that it is far from defeated. Bill Roggio urges Washington to break its habit of prematurely declaring victory and precipitously withdrawing, but instead to press its advantage:

Islamic State’s predecessor, the Islamic State of Iraq, which was really a front for al-Qaeda in Iraq, suffered a major defeat during the U.S. surge from 2006 to 2010. The Islamic State of Iraq controlled vast areas of the country prior to the surge; [it] responded [to its defeat] by going to ground and husbanding its forces. By early 2012, the group was back launching vicious attacks against Iraqi security forces, a prelude to Islamic State’s rampage in 2014. This same cycle has been seen in other theaters against jihadist enemies. . . .

Conditions in Iraq and Syria are ripe for this pattern to repeat itself. [The group’s head], Abu Bakr al-Baghdadi, and many key leaders remain alive. Thousands if not tens of thousands of IS soldiers are at the ready. The Syrian and Iraqi regimes are ill-equipped to deal with the long-term threat. [Moreover], IS is not the only threat that would be buttressed by a [premature] American withdrawal. . . . Al-Qaeda, which initiated the war on 9/11, has not been “decimated” and is not “on the path to defeat” as President Obama boasted years ago. . . .

[A] lack of commitment by the U.S. will also be taken as a sign of encouragement for state sponsors of terrorism, particularly Pakistan and Iran. Pakistan is arguably responsible for the deaths of more than 2,000 U.S. soldiers in Afghanistan. Without Pakistan’s support of the Taliban, it would not be able to maintain a viable insurgency. Iran has paid no price for backing Shiite militias in Iraq, which are responsible for the deaths of more than 600 U.S. soldiers. Disengagement [from Syria, Iraq, or Afghanistan] will be seen as a green light to use terrorism as a tool of statecraft.

The defeat of IS in Iraq and Syria is a welcome and necessary development in the war, and it was long overdue. But it was merely one battle in this long war. These jihadists remain committed to their cause, despite long odds against them. There is no question that the West possesses the resources and talent to defeat such an enemy. Does it have the will?

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.