In all three of their debates, President Obama and Mitt Romney both mentioned international trade and how it benefits the United States.

We signed three trade deals into law that are helping us to double our exports and sell more American products around the world, said Obama on October 3, referring to one of his administrations economic success stories.

I want to add more free trade agreements so we have more trade, said Romney on October 16, suggesting that hell pursue trade diplomacy even more aggressively.

Each time they faced off, the Democratic and Republican contenders were eager to talk trade. It didnt matter how the Commission on Presidential Debates tried to define the events it sponsored. The first debate focused on domestic issues, the last one concentrated on foreign policy, and the middle forum included both. Trade came up every time.

Yet neither candidate spoke directly about what may be the most essential point about the flow of goods and services across borders: U.S. trade policies prop up commerce all over the world. Global prosperity depends on an America committed to free-trade leadership.

This simple fact became obvious during the festivities surrounding the World Food Prize in Des Moines last month. My organization, Truth about Trade & tecnologia, held the seventh annual Global Farmer Roundtable, an occasion for farmers from different countries to gather and discuss their common challenges and opportunities. Aquest any, we hosted 15 agricultors de 13 nations, including Zimbabwe, Nova Zelanda, and Uruguay.

I wish Obama and Romney could have taken a break from the campaign trail and listened to our guests as they described how farmers and their families depended on the United States for leadership, vision and inspiration.

Because of the United States leadership, the world has come together to lower trade barriers, making it possible for farmers to feed the planet by selling what they grow to consumers theyll never meet.

Because of the United States leadership, biotechnology holds out the hope for greater agricultural productivity, making it possible to keep up with rising populations.

Because of the United States leadership, global shipping lanes are open and safe, making it possible for merchants to move their products without fear of coordinated military strikes or random acts of piracy.

Americans make all of this possible, but we benefit from it too. The presence of trade encourages peace and prosperity everywhere.

Think of it this way: Like the keystone that supports an arch, our trade policy connects domestic and foreign policy. If the keystone crumbles or vanishes, then the arch collapses, leaving only ruin.

In the third presidential debate, Romney came close to making this point. He cited Admiral Michael Mullen, the former chairman of the Joint Chiefs of Staff, who said that Americas top national security threat isnt China, Iran, or Russia. It isnt even Islamic terrorists. en comptes, its our national debt.

If the United States loses economic strength, then the world will become significantly less peaceful and prosperous. en comptes, it will descend into war and destitution.

Obama added his own observation: Weve got to make sure that our economy is strong at home so that we can project military power overseas.

The good news is that neither Obama nor Romney is a protectionist. From time to time, they have spoken harshly about Chinasometimes even a little too harshlybut they have refused to go over to the dark side of economic isolationism.

This is nothing to take for granted. In the heat of election contests, office seekers frequently try to pander to struggling voters by blaming foreign trade for Americas ills. a 2008, when he was a senator running for the White House, candidate Obama threatened to pull out of NAFTA.

Whether he truly meant what he said at the time or merely wanted to stoke populist passions is now a question for historians: As president, he abandoned this rhetoric and became an advocate of global commerce. Romney, for his part, has pledged to expand trade, especially with Latin America.

On Election Day, only one man can prevail. Lets hope that no matter who comes out on top, free trade triumphs as well. Then everybody wins.

Bill Horan cultiva blat de moro, soybeans and other grains with his brother on a family farm based in North Central Iowa. Bill volunteers as a board member and serves as Chairman for Truth About Trade & tecnologia (