President Trump is working to undo the domestic policies of Joe Biden. In foreign policy Mr. Trump is undoing the work of Woodrow Wilson.

The general understanding after World War I was that violations of national sovereignty and borders constituted the key threat to global peace. Addressing a joint session of Congress in January 1918, Wilson called for a “general association of nations” that would afford “mutual guarantees of political independence and territorial integrity to great and small states alike.” This was the League of Nations. It aimed to forestall conflict by making states sacred and their borders inviolable.

 

Meanwhile, European diplomats began drawing new borders throughout the globe. In the Middle East they established Jordan, Lebanon, Iraq and Syria. Mirroring Wilson, they spoke of self-determination in Africa, though decolonization didn’t truly begin until after World War II. In Europe, borders were redrawn to divide empires into nation-states.
Mr. Trump is rejecting that vision. According to him, the primary danger to global peace isn’t the infringement of state sovereignty but the actions of authoritarian terrorist regimes. Borders drawn in the 20th century haven’t provided security or self-determination; they’ve led to armed conflict. Syria has devolved into a brutal multiethnic dictatorship. Jordan’s majority-Palestinian population is ruled by an authoritarian monarchy with Bedouin roots. Gaza started as a territory under Egyptian control and turned into a vicious terrorist state. The Panama Canal has become a Chinese outpost.
Those shocked by Mr. Trump’s seemingly imperialist threats to take over Greenland, intervene in Panama, unilaterally rename the Gulf of Mexico and build American hotels in Gaza are using 20th-century principles to interpret 21st-century policy. Mr. Trump recognizes that the old rules don’t apply in a world of trade wars and terrorist organizations. What he proposes isn’t imperialism but a new line of Western defense against insidious forces.
Wilson believed that when authoritarian countries are given self-determination, democracy can emerge. George W. Bush and Barack Obama clung to this doctrine, advocating democratic elections in the Palestinian territories, Iraq and Egypt. Instead, fundamentalist Islam rose, endangering the region. Thousands paid with their lives. Where would you rather live, “democratic” Gaza or authoritarian Dubai?
In Wilson’s world, the preservation of state sovereignty was essential for free trade. In Mr. Trump’s world, it’s unreasonable to let major ports on both sides of the Panama Canal—which was built by the U.S.—be controlled by Chinese companies. U.S. intervention in the canal may compromise Panama’s sovereignty and impede trade, but the risks of Chinese influence in such a crucial waterway are far greater.
Wilson saw self-rule as the way to uplift nations and humanity as a whole. But it’s absurd for today’s U.S. to relinquish Greenland’s shipping routes, mineral resources and strategic benefits simply because the territory has enjoyed effective self-government for more than four decades. This is particularly true amid Russian and Chinese attempts to make economic and military encroachments on the island.
Wilson was right when he demanded in his 1918 speech that all armed forces withdraw from Belgium and honor the country’s sovereignty after years of devastating trench warfare. But Gaza isn’t Belgium. Gaza’s “sovereignty” was exploited by Hamas to perpetrate a massacre against Israelis, and Mr. Trump is right to try to abrogate its freedom to do so again.
As a child, I vacationed at a hotel on one of Gaza’s breathtaking beaches, which are unmatched in beauty throughout the Middle East. There’s no reason why, in the name of Wilsonian idealism, those beaches should host Iranian-funded terrorist squads rather than cocktails at sunset.