China, Russia and Iran are very different nations in very different parts of the world, but they have three significant commonalities. All were once empires; all are now ruled by men who aspire to build great empires anew; all regard the United States as their rival and adversary.

Al-Qaeda and the Islamic State also dream of an empire—one that would replace the Ottoman Empire, which collapsed in 1922, and its affiliated caliphate, which was abolished two years later.

Important to note: Iran’s rulers are not seeking to build a Persian or Iranian empire. Like Al-Qaeda and the Islamic State, they intend to resurrect a specifically Islamic empire, albeit one dominated by Shi’ites rather than Sunni Muslims.

Ayatollah Ruhollah Khomeini, who led Iran’s Islamic Revolution 40 years ago, was quite clear on this point. “Patriotism is paganism,” he said. Note that the most powerful institution he created was the Islamic Revolutionary Guard Corps, not—as you’ll sometimes hear it called—the “Iranian” Revolutionary Guard Corps.

Islamic imperialism, whether Sunni or Shia, is universalist—all conquered nations are to embrace a single theology. The same was true of Soviet imperialism—all the lands ruled by Moscow were expected to embrace Communist ideology.

Russian President Vladimir Putin, by contrast, aspires only to make Russia a superpower again. He has seized territory from neighboring Ukraine and Georgia, established military bases on the Mediterranean and, in the process, facilitated the slaughter of half a million Syrians and the displacement of millions more.

Chinese President Xi Jinping envisions a “great rejuvenation.” He is investing in a military that will be capable of projecting power not just in Asia, but far beyond. The regime annually steals hundreds of billions of dollars of intellectual property from both foreign governments and private companies. And it is using its economic muscle, through its “Belt and Road Initiative,” to make small nations around the world dependent and, in many cases, poorer. Xi will support autocrats who cough up the natural resources he needs and do as they are told.

On one level, none of this should surprise us. Empires have been rising, competing, conquering, exploiting, clashing and falling throughout history. But that history was supposed to end after World War II when Europe’s colonies achieved independence, and the United States. and its allies attempted to build a new world order—independent states that would not only peacefully coexist, but also would join an “international community.” All would abide by international laws and respect “international norms.” The United Nations was to be central to this effort. Its failure appears to me beyond dispute.

The European Community, established in 1957, went on to become the European Union—meant to be a “union of equals” that would establish “subsidiarity,” the principle of making decisions as close to the people as possible, in other words mostly at the local, regional or national level.

Instead, the E.U. has evolved into a kind of transnational or globalist empire, a concept political philosopher Yoram Hazony explores in-depth in The Virtue of Nationalism, his recently published and highly provocative book.

E.U. members have long had to acquiesce to the authority of politicians in Berlin—Germany is undisputedly first among equals—and unelected bureaucrats in Brussels.

More than two years ago, a majority of Britons expressed their dissatisfaction with this arrangement. To reclaim decision-making power and sovereignty, the British government has since been attempting Brexit. E.U. officials, reluctant to have their empire diminished and eager to discourage other members from following Britain’s example, have made the process a nightmare.

As noted above, China, Russia and the Islamic Republic of Iran, along with the various non-state jihadist groups, see the United States as the biggest obstacle to their ambitions. It’s therefore in their mutual interest to diminish American power and influence, and push Americans out of the regions they seek to dominate imminently.

The E.U. is ambivalent about the United States—more so than ever in the “Age of Trump.” Its officials have been working hard, if not successfully, to undermine American sanctions designed to pressure Tehran into changing its most malevolent behaviors.

West Europeans are also doing little to restrain Putin. Despite strong U.S. disapproval, German Chancellor Angela Merkel supports Nord Stream 2, a natural-gas pipeline project that will increase German dependence on Russia. (On Jan. 28, the Washington-based Fulbright Association is to award her its “Prize for International Understanding.” Remarkable, no?)

Former U.S. President Barack Obama did not see the picture I’m painting. He attempted to “reset” relations with Moscow and appease Tehran. He ignored China’s multiple transgressions. He declared victory over Al-Qaeda. He demanded little of the E.U.

U.S. President Donald Trump, by contrast, does appear to recognize the threats posed by revisionist, revanchist and rogue regimes, and he has taken a tougher line on E.U. burden-sharing. Still, the most consequential national security missions remain a long way from being accomplished.

Meanwhile, influential voices on both the left and the right are counseling retrenchment, telling him to end the “endless wars,” to “declare victory” on battlefields where victory has not been achieved, and to devote his energies to “nation-building at home.”

How is that not pre-9/11—indeed, pre-World War II—thinking? The neo-imperialists are intent on shaping a new world order, one that will be authoritarian, unfree and implacably hostile to American interests. Frustrating their ambitions won’t be easy. But the alternative, giving them free rein, would be reckless.