Donald Trump has the international order in his crosshairs. The business mogul’s bellicose (and often contradictory) positions—disband NATO, renegotiate trade pacts and permit the proliferation of nuclear weapons to Japan and South Korea—all strike at the heart of the global order that the United States has led since World War II. In the wake of that devastation, as John Ikenberry outlined, America fashioned a liberal Leviathan, “organized around partnerships and agreed-upon rules and institutions that facilitated restraint, commitment, reciprocity, and legitimacy.” This international system has served U.S. strategic interests, aided Washington’s allies, and provided stability and predictability for neutral parties and even putative rivals. By tying itself to an order built on a foundation of liberal norms, the American giant effectively crafted its own restraints; a Trumpian shattering of those checks should concern the American and foreign publics alike.

That the United States presided over the creation of a postwar order beneficial to itself and its allies should surprise no one. America guaranteed protection of its interests in Europe and Asia through elaborate alliance systems. Washington crafted international economic institutions conducive to free markets as part of the Cold War struggle. And, despite the scorn the United Nations evokes in some circles today, the United States took the lead in championing the new institution.

Yet these American initiatives, increasingly questioned by the Trump campaign, surpassed narrow self-interest; the United States elected to embed its vast military and economic might in a set of norms and principles that explicitly checked U.S. power. Consider that in shaping the UN Security Council, American planners gave their Soviet rival a veto on global security matters. American foreign policy leaders had deliberately chosen to craft a system that both constrained the United States from straying into unfettered hegemony and strove to move the world toward an era when an equal set of rules apply to all states, without distinction.

Donald Trump now challenges this global set of norms to which the United States subscribes. What else is Trump’s call to reassess U.S. participation in a host of international agreements, from trade pacts to the Geneva Conventions? Even the United Nations, a cornerstone of the international architecture, has not escaped his criticism.

To be clear, any attempt to “renegotiate trade deals and renegotiate military deals” in the first hundred days of a Trump administration would not only open a Pandora’s box, it would signal to the world a rejection of the self-imposed limitations that the United States has accepted for decades. At a minimum, such an action would result in a significant increase in strategic uncertainty; current U.S. support for the suite of principles and agreements underwriting the international order serves to indicate both American foreign policy interests and the limits of those U.S. objectives.

Beijing, for instance, may not like Washington’s presence in the South China Sea, but America’s de facto abidance by the UN Convention on the Law of the Sea gives credence to the notion that the United States’ ambitions do not extend beyond protecting freedom of navigation to pursuing unilateral domination of those waters. Without such explicit U.S. commitments as guides for America watchers, it becomes increasingly difficult to dispel the mutual mistrust surrounding the Sino-American relationship, stoking the potential for an accidental descent into great-power war.

The possibility for such uncertainty to spiral into inadvertent conflict is only enhanced by Trump’s apparent willingness to flirt with unilateral military force in any circumstance out of a fetishized desire to “never take any of [his] cards off the table.” Trump even seems willing to employ American military power to coerce partners, blithely claiming when pressed over how he will convince Mexico to pay for a wall along the border: “Mexico’s not going to be playing with us with war.”

Yet embracing such a policy undoubtedly runs counter to the United States’ decades of efforts to make resorting to force an obsolete method for resolving international disputes. The prohibition on the unauthorized use of military force found in Article 2.3 of the UN Charter, that “All Members shall settle their international disputes by peaceful means in such a manner that international peace and security, and justice, are not endangered,” is perhaps the cornerstone of the entirety of the liberal international order.

No, compliance with this principle has not been perfect. And at times, the United States has not matched its rhetoric in upholding this point (see arguments over the Iraq War, and even NATO’s intervention in Kosovo). Nonetheless, the overall U.S. track record illustrates that America has striven to promote this norm, for example, repeatedly choosing to go the extra mile for UN Security Council authorization in the 1991 Gulf War and the 2011 intervention in Libya.

Even in the case of Kosovo, the U.S.-led bombing campaign was carried out as a NATO operation only after the expenditure of considerable diplomatic efforts at the United Nations. The United States did not resort to immediate force; instead, it operated within a set of self-imposed constraints out of respect for the UN Charter and legitimacy of international public opinion—a stance which would crumble under a Trump presidency.

Finally, Trump’s much-touted desire to downgrade or disband America’s network of European and Asian alliances would remove a critical, if underappreciated, multilateral check on U.S. actions. Though Beijing and Moscow might initially rejoice at a withdrawal of American security commitments from their regions, the United States and its allies have a moderating influence on each other.

Washington is restrained—at points frustratingly so—by acting through alliances like NATO. At times, the need to maintain a coalition, or the requirement of unanimity among allies, has pulled the United States back from more assertive postures, as seen repeatedly in U.S. negotiations with European leaders over the appropriate transatlantic response to Russian actions in Ukraine. Conversely, U.S. security guarantees and troop presences have reassured local actors, and thereby tempered what would otherwise need to be more forward-leaning allied defense postures.

Under a Trump policy committed to avoiding “free-riding” allies, there is no guarantee that the United States will have to consider partners’ views. Such a transformation would be a catastrophic rejection of the inclusive and consultative approach that drew countries to U.S. leadership throughout the Cold War. Trump’s United States would be a cursed superpower—one rich in military strength, yet poor in friends; one ever afraid, yet consistently terrifying its neighbors; one endlessly trumpeting its own importance, yet increasingly disdained by the globe. America would be “great,” a giant on the world’s stage, yet it would be a hollow colossus, a nation isolated, scared and laying the seeds for its own downfall.

Will Moreland works at a leading Washington, D.C., think tank where he specializes in U.S. foreign policy, geopolitical rivalries, and American grand strategy. He holds a Master’s in Foreign Service from Georgetown University.

Image: Flickr/Gage Skidmore