As representatives from the world’s leading economies gather for the G20 Summit on April 2, it’s worth remembering the last time London hosted a summit with the aim of reviving a slumping global economy and collapsing trade flows. As the BBC reminds us, "In June 1933, delegates from 66 countries gathered in London to try and agree plans to revive the world economy in the midst of the Great Depression."

The parallels are not pleasant. The World Trade Organization recently forecast global trade would fall 9% in 2009 due to the shrinking global economy, the biggest fall since the Great Depression. 

Leading the U.S. delegation in 1933 was Cordell Hull, who ultimately became America’s longest serving secretary of state. Hull went on to win the Nobel Peace Prize for his work building international institutions, including those that promote trade. He devised the model of trade negotiations in which countries offer one another market access on a reciprocal basis -- trading away their tariffs in order to spur trade, growth, and jobs.

In other words, the father of modern American trade policy was a Democrat serving under President Franklin D. Roosevelt at the height of the New Deal -- a point worth considering amid the challenges of today’s trade politics.

In his memoirs, Hull expressed pride that U.S. trade agreements "were ultimately to be concluded with thirty-seven nations. When many other nations saw [their] possibilities they embraced such agreements not only with ourselves but also with one another. War on three continents was to interfere with its application, but it came to be recognized among the clear thinkers of all nations as the only way out of commercial chaos and as one of the main factors for peace.”

Hull addressed the U.S. Chamber of Commerce on May 2, 1935, and offered words of courage that ring true to this day:

The pressure which is being currently brought upon both legislators and officials in Washington by those who fear that they are to be deprived of even a small part of the artificial advantage given them by an overindulgent Government, too often at the expense of efficient producers and consumers in general, would incline one to believe that much of the sturdy self-reliance, hardihood, and vigor of this country is definitely on the decline…

It is incumbent upon some great nations, certainly the United States as much as any other … to supply the inspiration necessary to induce them to alter their course and to hope that the world can shortly expect a general movement in the direction of international economic sanity.

Or, as he later said in a more pithy way: "Where trade crosses borders, armies do not."

In the long run, Hull’s legacy was to include the post-war General Agreement on Tariffs and Trade, which allowed trade to expand from $80 billion in 1947 to about $20 trillion last year, boosting incomes in country after country.

We hope the delegates to this London conference remember the wisdom of Cordell Hull and the lessons of history.