In the mango and cashew groves of the Casamance region of Senegal, Handicap International demining teams are now removing deadly land mines sunk into the earth during a long-ended conflict.

The State Department is not only financing these efforts but also attended international discussions on the land mine ban treaty held recently in Geneva. Over the past two decades, the United States government has led the rest of the world in funding mine action initiatives, spending more than $1.3 billion worldwide.

In Geneva, the State Department delegation met with representatives of the more than 158 signatory countries to discuss the treaty’s systematic and effective implementation.

We applaud the United States for supporting the life-saving and painstaking work of removing land mines from the soil of countries like Senegal, Laos and Mozambique.

But the irony here is inescapable. Just as the United States pays to remove mines around the world and sends officials to attend international meetings on effective implementation of the Mine Ban Treaty, it refuses to take the final step of relinquishing antipersonnel land mines and signing the Mine Ban Treaty. That refusal means the United States remains mute in actively fighting the scourge of land mines as it quietly pays for deminers to sweep clean field after field.

Land mine contamination continues to be a worldwide crisis. Last year, almost 4,000 civilians were killed or maimed by a land mine in one of 66 mine-affected countries. That’s 10 civilians every day. Funding for demining and victim assistance saves countless lives and provides access to assistance for hundreds of thousands of people injured by these weapons.

However, despite the progress made, millions of uncleared land mines continue to threaten people living in affected regions like the Casamance in Senegal, making routine activities, such as going to school or farming, potentially lethal. New land mines are still being laid. In April we learned that Moammar Gadhafi’s forces in Libya used land mines in their conflict with rebels.

Elizabeth Sambou, a Handicap International deminer who clears land mines in the Casamance, understands the importance of clearance. She has overcome the fear of her work because she knows her efforts will eventually restore access to land, allowing people to reclaim their daily lives and livelihoods.

“These people have suffered for years,” she said. “They need access to their land as fast as possible. These are the fields that feed them.”

We first witnessed the damage done by land mines 30 years ago when we began to work with Cambodian refugees fleeing into Thailand through western Cambodia — at that time one of the most land mine-infested territories in the world. Many people lost limbs while escaping across the border and our first projects sought to find affordable ways to construct prosthetic devices for the survivors. In the early 1990s, when land mines were injuring or killing 20,000 to 25,000 people a year, we joined with a number of other nongovernmental organizations to convince governments to ban all uses of this weapon.

The Mine Ban Treaty has successfully stigmatized and created an international norm against the weapon. Today, 158 nations are signatories; only one country, Burma, used land mines last year. Casualty rates are a fraction of what they were 20 years ago. Eighty-six parties to the treaty have eradicated their stockpiles, collectively destroying more than 45 million antipersonnel mines.

Despite the obvious moral and humanitarian reasons for joining this treaty, the United States has yet to do so. Joining the treaty would ensure that the United States never uses the more than 10 million land mines currently stockpiled in U.S. arsenals.

But U.S. compliance would also eliminate the excuse used by other key powers, including Russia, China, Vietnam, Pakistan and India, for not joining the treaty. If the United States joins the treaty, those powers can no longer hide behind the U.S. refusal as justification for their own absence.

In December 2009, President Barack Obama’s administration initiated a comprehensive review of U.S. land mine policy, which now seems to have stalled. Given the clear moral imperative to join this treaty, it is increasingly difficult to fathom why the United States has not taken this final step, especially since there do not seem to be any costs to joining. After all, the United States has not used antipersonnel mines since the 1991 Gulf War — 20 years ago. It banned export of the weapons in 1992, and ceased production in 1997 .

As the winner of this year’s Conrad N. Hilton Humanitarian Prize, we join with 16 Nobel Peace Prize laureates and 68 U.S. Senators (68 is one more than the two-thirds majority needed for Senate ratification of the treaty) who have urged Obama to join the 158 other countries, including all of our NATO allies, that have signed the treaty.

This administration claims it is serious about a renewed emphasis on multilateralism and disarmament; joining the Mine Ban Treaty would certainly underscore this commitment, and ensure that this horrific weapon is never used again.

Jean-Baptiste Richardier, M.D., is a co-founder of Handicap International and executive director of the Handicap International Federation. Elizabeth MacNairn is executive director of Handicap International in the United States.