President Trump this week reaffirmed a promise to withdraw thousands of American troops from Germany. His plan was attacked by members of his own party serving on the House Armed Services Committee for what was called a “Republican War” by the editor of the National Interest.

Thirty decades ago, as the Cold War was ending, former United Nations Ambassador Jeane Kirkpatrick sensibly wrote that it was finally time for “drawing down American forces and commitments overseas.” Since the late 1930s, she declared, the United States had an “unnatural focus” on foreign affairs, and the end of the Cold War provided an opportunity for the United States to become “a normal country in a normal time.”

Rather than embracing her advice, however, the United States not only retained such overseas presence across Europe and Asia, it also greatly increased American troops and alliances in the Middle East. Why is it so hard to move back to “a normal country in a normal time”? One clue to answering this question is found in the Republican members of House Armed Services who criticized the withdrawal plan for Germany.

For the past two election cycles, these Republican members of Congress have collected nearly $5 million in campaign contributions from defense contractors, according to data from Open Secrets. Defense contractors are one industry sector that retains strong pecuniary interests in having the United States retain military commitments across the world.

The willingness of these Republican members of Congress to oppose the president of their own party on a critical security matter signifies that the warning about the military industrial complex must be heeded. President Eisenhower said, “This conjunction of an immense military establishment and a large arms industry is new in the American experience.” He added, “The total economic, political, even spiritual influence is felt in every city, every state house, and every office of the federal government.”

We have some obvious reasons for reducing the financial commitment to protect Germany, as the United States is witnessing exploding debts and deficits. The United States is broke, while Germany is not. In order to deal with the fallout of the pandemic, Germany will increase its borrowing this year to 7 percent of gross domestic product, while the United States will increase its borrowing to 18 percent of gross domestic product.

According to data from the World Bank, the economy of Germany is now over twice the size of the economy of Russia. Germany is thus capable of protecting itself against Russia and it could also be more than capable of protecting its European neighbors. So the United States cannot afford to offer such broad security protections to wealthy countries. Trump should understand that if we can convince Germany and others to invest in their security, the benefit for us must be reduced defense spending.

A more important reason to curtail our military commitments is because a democracy that overreaches does not last. Athens experimented with this but its democracy fell when imperial ambitions led its army to the bottom of the quarry in Syracuse and its navy to the bottom of the Mediterranean. Ancient Rome ceased to exist as one of its imperial military commanders “crossed the rubicon” and diminished authority of the senate.

The most patriotic reason to lessen our military commitments is found in the lessons of history and the warning by Eisenhower. A democracy that overreaches and embraces empire inevitably ends in tragedy.

William Smith is the director of the Center for the Study of Statesmanship with Catholic University. He is the author of Democracy and Imperialism.

Article originally published at The Hill.