In recent decades, as China adopted a sharply muscular approach to the Pacific Ocean, other countries began to sound the alarm, decrying Beijing’s pushy new attitude toward a region full of much smaller and weaker countries.

Although China seemed to be adopting a bygone and largely discredited maritime strategy employed a century earlier by Western powers, many of its tactics were novel. As it pressed legally and historically dubious claims to outright ownership of nearly all of the South China Sea, Beijing boldly built artificial islands from dredged sand in far reaches of the ocean for use as military outposts to enforce its control.

In recent decades, as China adopted a sharply muscular approach to the Pacific Ocean, other countries began to sound the alarm, decrying Beijing’s pushy new attitude toward a region full of much smaller and weaker countries.

Although China seemed to be adopting a bygone and largely discredited maritime strategy employed a century earlier by Western powers, many of its tactics were novel. As it pressed legally and historically dubious claims to outright ownership of nearly all of the South China Sea, Beijing boldly built artificial islands from dredged sand in far reaches of the ocean for use as military outposts to enforce its control.

China seized and sank vessels and used powerful water cannons to warn away those from other Asian nations that did not respect its writ, oftentimes in water far closer to the shores of these neighbors than to China’s terrestrial boundaries. In one incident in 1988, it opened fire on Vietnamese soldiers who were pressing a rival claim to a tiny island, reportedly killing 64 people.

Late in the Obama administration, the United States began to push back against China’s maritime policies. It provided diplomatic support for China’s neighbors in these face-offs, invoked international tribunal rulings that invalidated Beijing’s expansionist claims, encouraged Asian countries to bolster their defense cooperation, and stepped up U.S. naval patrols in the region as a warning to China that its pushiness could ultimately bring about Washington’s direct involvement in containing Beijing and enforcing international law.

Unstated by either power was that the clearest model for China’s behavior was the United States itself, which since the 19th century had articulated the Monroe Doctrine, a foreign-policy position that accorded it a dominant status in the Western Hemisphere. The doctrine included special rights and privileges for the United States, including a rejection of any regional security role for Old World powers. Now, just as a fast-rising United States had once done in the Caribbean and much of the western Atlantic Ocean, Beijing was treating the surrounding seas as something akin to a Chinese lake.

This history has become newly relevant in recent weeks as the United States has begun reenacting a form of gunboat diplomacy toward its southern neighbors with profound implications for international law and order. Under the pretext of fighting a “war” against illegal narcotics trafficking, U.S. President Donald Trump’s administration has ordered the dispatch of the world’s largest aircraft carrier to the Caribbean, blown up boats from Latin America with little evidence of prior knowledge of their cargo or passengers, and increasingly threatened South American countries such as Venezuela and Colombia.

Trump has been uninhibited in his unilateralism, his interpretation of executive power, and his lack of concern for legal niceties. “I don’t think we’re going to necessarily ask for a declaration of war. I think we’re just going to kill people that are bringing drugs into our country. OK?” he said on Thursday.  “We’re going to kill them. You know? They’re going to be, like, dead.”

Trump’s aggressiveness in what he is now treating as a U.S. lake is troubling for its domestic implications involving the rule of law—due to what amounts to extrajudicial killings—along with a disrespect for legal norms about the use of military power. These call for congressional oversight and approval as well as much greater public transparency over the aims of the campaign and the identity of those who are being killed.

These military actions fall within a larger pattern of lawlessness in this administration, which has included the use of the Justice Department to persecute Trump’s personal enemies, the decision to pardon wealthy businesspeople with ties to his family, the legally dubious deployment of the military to U.S. cities, and the acceptance of money from rich donors to fund pet projects such as the destruction of the White House’s historic East Wing to make way for a vast new ballroom.

There is little sign that either the president or his defense secretary, Pete Hegseth, have any depth of knowledge about Washington’s past gunboat diplomacy or its terrible legacy of political and military interventions in Latin America—usually in support of authoritarian governments that went on to compile atrocious human rights records, including Brazil’s military dictatorship and the Pinochet regime in Chile,.

Equally worrisome, though, is the sense that the Trump administration has devoted little time or effort to assessing the potential impact of its recent aggression toward its neighbors on the behavior of a newly muscular and revisionist China. Trump’s actions have made it all but impossible for the United States to lodge a principled objection to any domineering behavior by China in the South China Sea or the Sea of Japan, where Tokyo—a U.S. ally—and Beijing maintain rival territorial claims.

If China decides to sink the Sierra Madre—a long-crumbling ship that the Philippines has struggled to provision as a manned outpost to sustain its claims to the waters off its shores—Beijing can simply point to Washington’s unilateralist and extralegal approach in Latin America as justification for its own actions. The same would be true in any future showdown between Vietnam and China’s far more powerful navy. Given China’s growing strength, in fact, it is hard to imagine any limits to its behavior at all. What principled complaint could Washington make if Chinese naval or coast guard vessels were to ram or sink a Japanese counterpart?

In other words, Washington under Trump has given a powerful boost to a rising global ethos based on the law of the jungle—or, in other words, might makes right.

Even if Trump were faced with such objections—say, by some historically minded and brave Cabinet member, whomever that might be—one can imagine him still brushing off any reservations. His whole modus operandi, after all, seems to revolve around the benefits and privileges that stem from power, and right now, at least, the United States remains the world’s premier military power.

Yet power is relative, not static, and U.S. power—though vast and still virtually unmatched—has been in relative decline for years. More than anything else, that is due to the recent sharp rise of China, which now has a larger navy than the United States, along with far greater shipbuilding capacity, underpinned by decades of growing prosperity.

Power is also relative in terms of distance. There is no necessary contradiction between the United States being the world’s preeminent military power and it being reduced to relative powerlessness vis-a-vis China the closer one gets to what Beijing considers its home waters.

Here is where international law versus the embrace of lawlessness shows its merit. As long as the United States is on the side of the rule of law—and here, maritime law in particular—it enjoys international legitimacy and a platform that is propitious for convening allies and sympathetic states motivated by a shared sense of principle.

But once the rule of law becomes the law of the jungle because of Washington’s own actions, the United States becomes just another bully at worst and just any old country at best instead of a nation to rally around. And once the laws of distance come into play, it may find that its power has been irrevocably frittered away.