The U.S. Senate might be on the verge of maximizing the world’s ROI on a meeting that took place twelve-and-a-half years ago.

In an economy that measures results in annual and quarterly cycles, it’s inconvenient that the takeaways from some meetings can take more than a decade to appear. But if President Barack Obama signs the global land mine treaty, at the urging of 68 U.S. Senators, the decision will resonate around the world and put meetings ROI in a slightly different light.

The Mine Ban Treaty conference took place in Ottawa December 2-4, 1997, and (full disclosure) documenting it stands as one of our firm’s proudest moments. Since the conference, 156 countries have signed the treaty, and land mines have been cleared from more than 1,200 square miles of territory. But freeing the world of land mines will be a multigenerational task, and one way to make the treaty whole is for the world’s biggest military power to ratify it.

It’s hard to imagine a gathering with a more profoundly important ROI than the Mine Ban Treaty conference. Land mines have killed more civilians than both world wars, and they impede economic and social development wherever they’ve been deployed. After 14 months of intensive negotiations involving many, many face-to-face meetings, diplomats from around the world gathered to ban a product that has been described as “a weapon of mass destruction, moving in slow motion.”

There are at least two lessons in the U.S. government’s long relationship with the land mine treaty—that you don’t quit when the results really matter, and that the best measures of meetings ROI don’t always fit within the neat boundaries of a conference schedule, a post-event recap, or an annual report or financial statement. In 1997, Sen. Patrick Leahy, D-Vt., tried mightily to get the Clinton White House to sign on during the Ottawa Treaty Convention. Fast forward a dozen years, and Leahy and Sen. George Voinovich, R-Ohio, have finally patched together endorsements from 68 Senators, more than the two-thirds majority needed to ratify the treaty.

There’s no methodology to track the impact of one meeting through 50 rounds of quarterly reporting. An association’s annual meeting or a corporate sales meeting that takes place this spring will be subject to intensive measurement over the next three to 12 months. But by 2011, it will be part of the base line for next year’s program, and by 2012 or 2013, it will be ancient history.

That cycle may be familiar, but it doesn’t properly value some of the most important work we do on site. Participants know that a chance conversation in a hallway could be the start of a groundbreaking discovery that makes it to the plenary stage, or the awards banquet, five years later. And a meeting like the Mine Ban Treaty conference can make a difference for generations to come, even if it’s just one crucial link in a chain of ROI.

Avaaz.org has launched an online petition urging President Obama to sign the treaty. You can sign the petition here.

In other news, MPI has just released an action guide and presentation slides based on the Meetings Deliver white paper that circulated at MeetDifferent 2010. Get involved today!

Mitchell Beer, CMM, is president and CEO of The Conference Publishers Inc., one of the world’s leading specialists in capturing and repurposing conference content. Beer blogs at http://theconferencepublishers.com/blog. Send comments, facts, arguments, or column ideas to mitchell@theconferencepublishers.com.