The left is thinking about foreign policy, sort of. Last October, Vermont Senator Bernie Sanders gave a speech at Johns Hopkins, calling for a new progressive internationalism. Trumpism, he said, is as borderless a problem as rising CO2, and Donald Trump but a node on a corrupt global “network” of “authoritarianism, oligarchy, and kleptocracy.” “Our job,” Sanders said, “is to rally the entire planet.” Recently seated members of the House, especially representatives Ro Khanna and Ilhan Omar, have also challenged previously consensus positions, especially support for Israel and Palestine.

This new attention to international relations is a welcome development, for, as nearly all of United States history shows, the political coalition that dominates foreign policy dominates domestic policy. Foreign policy is the realm where aspiring governing elites establish hegemony, not only over other countries but within this one, reconciling contradictory interests and ideas, and unifying domestic constituencies. Donald Trump’s Venezuela putsch, for example, reorders international relations, while deftly keeping Florida’s electoral votes and setting the terms of the 2020 presidential election: America will never be socialist.

Sanders’s vision of a just world is ambitious and sweeping, and maybe it will help the left establish domestic legitimacy and advance domestic reform. But it also raises a question. The projection of global power has, over the years, strengthened militarism, justified interventionism, and reinforced corporate power—all the things the left is committed to fight against. Can progressives put forward an internationalism that isn’t linked to war and corporate power?

The United States was founded on the idea that expansion was necessary to achieve and protect social progress. Over the centuries, that idea was realized, again and again, mostly through war. Extending the vote to the white working class went in hand with removing Native Americans, stealing their land, and then stealing Mexican land, thefts that served as the foundation of white settler democracy. The Union Army defeat of the Confederacy didn’t just end slavery, but marked the beginning of the final pacification of the West. Millions more acres were distributed to veterans. Never before in history could so many white men consider themselves so free, winning a greater liberty by putting down people of color, and then defining that liberty in opposition to the people of color they put down.

Go further down the line: There’s no moment of political reform, no widening of the promise of liberalism to oppressed groups within the nation, that didn’t entail a projection of power outside the nation. The interdependent relationship between domestic reform and foreign expansion is complicated. Sometimes the link was ideological: Breaking up the Spanish Empire in the Caribbean and the Philippines, Theodore Roosevelt and Woodrow Wilson believed, would create a sense of national purpose that could be used to break up the trusts at home. Other times the link was nakedly transactional: Some suffragists would trade Woodrow Wilson their support for U.S. entry into World War I for his support for their campaign, as did some trade unionists for labor reform. The connection could be economic: In the 1930s, Franklin Delano Roosevelt struck trade deals with Latin America that won him the support of pharmaceutical, chemical, airline, petroleum, and electronic companies, and in return they supported the New Deal’s gradual expansion of domestic liberalism. And the relationship was always political: Civil rights activists leveraged Cold War rivalry to press their claims for equal rights at home. Meanwhile, military service became a primary mechanism of social mobility, giving African Americans access to benefits such as education, housing, and health care, through all the twentieth century’s many wars.