Patrick Murphy is a retired Army captain and Iraq War veteran who served in the U.S. House of Representatives as a Pennsylvania Democrat. He is working for the Department of State in support of efforts to secure ratification of the Disabilities Treaty. This op-ed originally appeared in Stars and Stripes.

Everyone who has worn the uniform of the United States knows that fighting for our country doesn’t stop when deployment ends. Our duty to our fellow soldiers, and our fellow citizens, is a lifelong promise made when we joined the greatest fighting force the world has ever known. It is a promise I made proudly nearly 20 years ago and one I intend to keep by fighting for the tens of millions of disabled Americans and the millions of disabled American veterans.

I am standing up for them, and a generation of servicemembers returning home from a decade at war, by calling for the passage of the Disabilities Treaty. This critical international agreement will make it easier for our veterans to study, work and travel overseas.

I served in Baghdad from June 2003 to January 2004. I led convoys and saw firsthand the courage and sacrifice made by my fellow soldiers. When I returned home, I saw the same from our vets. Many of them left arms and legs on the battlefield in service to this country, and they deserve our continued support.

The Disabilities Treaty is a commonsense step that we can take to keep faith with our disabled veterans. It will put the United States in the driver’s seat as we promote our standards for accessibility and equality of opportunity in other countries, making it easier for our wounded warriors and their families to take advantage of opportunities abroad.

I know there are a lot of urgent issues that consume our leaders in Washington. Believe me, as a former congressman, I felt the pull of those issues day in and day out. But what treaty advocates are talking about isn’t pie-in-the-sky internationalism. There are 55 million disabled Americans in this country, including 5.5 million disabled American veterans. Ratifying this treaty is real to them and their families.

So why join the treaty? As I saw in Iraq, Bosnia and in many other countries in which I’ve traveled, accessibility standards overseas aren’t nearly as good as our own. In fact, while 42 International Security Assistance Force (ISAF) members in Afghanistan have ratified the treaty, many of them still have barriers for people with disabilities that make finding jobs or getting around a day-to-day challenge.

But the challenge isn’t just in 42 ISAF countries. It’s systemic and it will require systemic reform.

Consider this: More than 325,000 American servicemembers and their families are stationed abroad in countries with low accessibility standards. Nearly 20 percent of beneficiaries of the Post-9/11 GI Bill have a disability, and many of them are deterred from studying abroad precisely because of these low standards. That’s unacceptable to me not just as a veteran, but as an American.

When we passed the Americans with Disabilities Act in 1990, we set the gold standard for employment and accessibility for people with disabilities. We need to export that standard to the world, and joining the treaty will help us do that without adding a cent to our budget.

It will put us in the best position to push other countries to meet our standards. It will ensure continued American leadership on disability issues. And it will open economic opportunities for our veterans in a world where flexibility in the labor market and traveling abroad is an essential ticket to success.

We had a saying in the Army: “Lead, follow or get out of the way.” The United States takes care of our own and we leave no one behind. When it comes to the Disabilities Treaty, it’s time that America took the lead on behalf of our veterans and disabled Americans all across the world.