Donald Trump’s Threat to the Global World Order

Opinion|We’re About to Find Out How Much America’s Leadership Matters

The global legal order rests on a kind of collective act of faith. For it to work, nations must trust that other nations will behave as if its principles matter. The system is not so unlike the dollar in this respect: It holds value only when — and only because — most of those who use it believe that it does.

This is why Donald Trump’s re-election to the American presidency is such a threat to global peace and security. He is — as an elected official and as a person — committed to breaking principles, not maintaining them. He understands and appreciates the value of the dollar. The global legal order? Not so much.

The last time he was president, Mr. Trump withdrew from critical treaties, launched what critics have deemed unlawful military strikes in Syria and on the Iranian general Qassim Suleimani in Iraq, and set off a damaging trade war with China. This time, his incoming administration appears poised to do far worse. His choice for national security adviser, Representative Michael Waltz, introduced legislation last year to use military force against drug cartels in Mexico. His pick for defense secretary, Pete Hegseth, has championed service members accused or convicted of war crimes. His choice for director of national intelligence, Tulsi Gabbard, is an apologist for both the Syrian dictator Bashar al-Assad, who has massacred his own people, and Russia’s president, Vladimir Putin, who started an illegal war on Ukraine and is under an arrest warrant from the International Criminal Court.

Together with Mr. Trump’s, their ideas embody the rejection of a system that is grounded in the idealistic — but until now remarkably successful — faith in the willingness of nations to abide by a set of shared principles that guide their behavior. If they have their way and America’s commitment to supporting this legal order ceases, we may find out how much the global rules — and principled American leadership in support of them — really matter.

For 80 years, chief among these principles has been the prohibition on war, and, with it, territorial conquest. This was not always a given. For much of modern history, nations operated in a system in which “might makes right.” It was in the years after World War I that nations first renounced the resort to war “as an instrument of national policy.” In 1945, with Germany and Italy having surrendered and Japan on the brink of defeat, 50 nations gathered in San Francisco to sign the United Nations Charter, which declared that “all members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state.” This commitment has been remarkably effective: Wars of aggression and territorial conquest, once common, have become exceedingly rare.

This transformation created the foundation for a new global order. It gave rise to a host of new international organizations — the United Nations, the World Bank and the World Trade Organization, to name a few. And it set the stage for thousands of international agreements, from the 1949 Geneva Conventions to the 1970 Treaty on the Non-Proliferation of Nuclear Weapons to the 2016 Paris Agreement on Climate Change. With nations largely free of fear that trading partners would attempt to seize the gains from trade by force, global trade has flourished. Peaceful cooperation among countries is at a high — on everything from human rights to freedom of the seas to exploration of outer space to public health.