President Donald Trump’s call to “take over” Gaza, relocate 2 million Palestinians elsewhere, and build the “Riviera of the Middle East” under a U.S. “long-term ownership position” may never happen. However, simply suggesting it puts Americans directly in the gunsights of Islamist extremists—not just in the United States but around the world.

Research shows that foreign military occupation is the leading cause of the worst forms of terrorism—suicide attacks—and has also led to the rise of the terrorist groups that use these deadly tactics.

On Sept. 11, 2001, the United States suffered the deadliest terrorist attack in history, when 19 Islamist extremists recruited by al Qaeda leader Osama bin Laden willingly gave their lives to kill nearly 3,000 Americans. Shortly thereafter, I compiled the first complete database of suicide attacks around the world to understand why. At the time, the world leader in suicide terrorism was the Tamil Tigers in Sri Lanka, a nonreligious majority Hindu group that carried out more suicide attacks than Hamas or Palestinian Islamic Jihad.

What most suicide terrorist attacks have in common is a specific secular and strategic goal: to compel foreign occupiers to withdraw military forces from territory that the terrorists consider to be their homeland. Religion is rarely the root cause, although it is often used as a tool by terrorist organizations in recruiting.

In 1982, Israel’s military occupation of southern Lebanon spawned Hezbollah, which used suicide attacks to deadly effect. Israel’s increasing military occupation of the West Bank and Gaza led to the rise of Hamas. In the 1990s, the prolonged U.S. military presence on the Arabian Peninsula was the best recruiting tool for bin Laden’s campaign of suicide terrorism against the United States. And the data through 2022 shows that the close association of foreign military occupation and suicide terrorism has continued.

Most prominently, the U.S. occupation of Afghanistan and Iraq led the Afghan Taliban to begin its own campaign of suicide terrorism and gave birth to al Qaeda in Iraq, which later morphed into the Islamic State, creating an enormous wave of anti-American suicide attacks that only subsided with the withdrawal of U.S. forces from the region.

For years, Americans have assumed that the danger of Islamist terrorism is over or, at least, not going to touch their lives. However, Trump’s proposal for the United States to occupy Gaza on a permanent basis is bound to rally Islamist extremists across the Middle East—not just what’s left of Hamas but also al Qaeda, the Islamic State, and others—against Americans.

Proposing to seize Gaza gives powerful substance to the long-standing Islamist narrative that the United States is the real threat. Ordinary Americans will pay the price.