Seventy years after American and allied forces launched the largest amphibious assault in history, world leaders convened today on the beaches at Normandy to honor the enduring legacy of those who fought to defend freedom against tyranny and to defeat the Axis Powers. Yet as we remember the great sacrifices of Americans and our allies to win World War II, it’s timely to recall what the United States also did to help win the peace after the war: namely, invest U.S. foreign assistance to help rebuild the war-torn nations of Europe and Japan, and eventually transform them into major U.S. allies and indispensable trading partners.

World War II devastated Western Europe, inflicting a staggering death toll on combatants and civilians, and destroying homes, buildings, factories and key infrastructure essential to economic commerce across the continent. The physical damage was so severe that in May 1947, nearly two years after Victory in Europe Day, Winston Churchill described Europe as “a rubble-heap, a charnel house, a breeding ground of pestilence and hate.”

At the time, leaders in Washington understood that the United States had a powerful strategic interest in helping Western Europe to recover and stand on its own. As Secretary of State George C. Marshall said on June 5, 1947: “Our policy is directed not against any country or doctrine but against hunger, poverty, desperation and chaos. Its purpose should be the revival of a working economy in the world so as to permit the emergence of political and social conditions in which free institutions can exist.”

That’s why the United States worked to rebuild post-war Europe, investing $22 billion — or roughly $182 billion in real 21st-century dollars adjusted for inflation — in economic foreign assistance across 16 war-torn nations from 1946 to 1952. To be sure, America’s post-war commitment to Western Europe demonstrated our nation’s character. Yet it also advanced our economic interests. America’s $182 billion in economic foreign assistance to Europe amounts to far less than the more than $250 billion in goods that the United States now annually exports to those countries.

The economic relationship between the United States and the 27-nation European Union today is the most advanced in the world, with the two blocs exchanging roughly $2.7 billion in goods and services each day. What’s more, Washington and Brussels are currently negotiating the Transatlantic Trade and Investment Partnership, a far-reaching agreement that could further boost U.S.-European economic ties by further reducing red tape and investment barriers on both sides of the Atlantic.

After World War II, the United States also understood the strategic importance of using foreign assistance and other tools to aid and rebuild post-war Japan. Between 1946 and 1952, Washington invested $2.2 billion — or $18 billion in real 21st-century dollars adjusted for inflation — in Japan’s reconstruction effort. That amounts to more than one-third of the $65 billion in goods that the United States exported to Japan in 2013. Today, Japan is a mature democracy, the world’s third largest economy and one of America’s most important allies in the Asia-Pacific.

Decades after World War II, foreign assistance programs are still helping Washington to advance America’s core national security interests by promoting economic development and regional stability, while at the same time opening and expanding international markets for U.S. businesses. The United States successfully did this in post-war South Korea, and it has the opportunity to do it again in other parts of the world.

Consider sub-Saharan Africa, where frequent energy shortfalls inhibit business activity and commercial growth, making it difficult for children to attend school, companies to create jobs and businesses to buy or produce goods. The U.S. House of Representatives passed legislation in May 2014 aimed at expanding electricity access across sub-Saharan Africa. Originally introduced by a bipartisan group of lawmakers led by House Foreign Affairs Committee Chairman Ed Royce, R-Calif., and Ranking Member Eliot Engel, D-N.Y., the bill would establish “a U.S. strategy to support affordable, reliable electricity in sub-Saharan Africa in order to improve economic growth, health and education in Africa, while helping job creation in the United States through greater exports.” The idea is to work with regional governments and the private sector to create more dependable electricity access, develop more predictable regulatory environments, and improve overall government transparency. Doing so would not only reduce global poverty, but also expand sub-Saharan Africa’s existing consumer base for U.S. businesses and goods. In short, it would eventually transform America’s relationship with the region from one based on foreign aid to one anchored on foreign trade.